Two jars sit on the counter. Same weight, same category, and one costs about twice what the other does. The budtender says the expensive one is better bud, and points at a number on the label.
That answer is incomplete, and the gap between the two prices is made of four different things: how much you are buying, what the grower did, what the shop decided to call it, and what the state takes at the register. Only one of those four is printed on the jar.
Here is what each layer is actually doing.
The weights, and why they are strange numbers
Flower is sold by fractions of an ounce, which is why the numbers look arbitrary until you see where they come from.
- A gram is the smallest common unit, usually sold as a single pre-roll or a sample jar
- An eighth is 3.5 grams, one eighth of an ounce, and the most common flower purchase in legal retail
- A quarter is 7 grams, a half is 14 grams, and an ounce is 28 grams
The ounce is nominally 28 grams rather than the 28.35 a scale would give you. That rounding is convention across the industry, and state possession limits are generally written in grams rather than ounces, so the two systems sit side by side on the same menu.
Larger weights cost less per gram, and the size of that discount has been measured. A 2025 study in the International Journal on Drug Policy analysed 710,588 flower products from 3,693 dispensaries across 30 states and Washington D.C., and estimated a weight elasticity of price of -0.18. In plain terms: buying a bigger jar lowers your cost per gram, reliably but not dramatically. An earlier analysis of roughly 31 million purchases in Washington State put the bulk discount even smaller.
So buying an ounce instead of four eighths saves money. It saves less than most people assume, and it only saves anything if you actually get through it before the terpenes go — which is a real constraint, covered in our guide to reading a weed label.
The tier words are not a grade
Top shelf. Mid. Value. Smalls. Exotic.
No agency defines any of these. There is no inspector, no certification, no published standard. Unlike beef or eggs or olive oil, cannabis has no regulated grading system, so the tiers emerged from industry convention and shop-by-shop judgment. The indica, sativa and hybrid labels sitting next to them are a looser guide than most menus imply, for related reasons. The words on the shelf card mean what that particular store decided they mean.
That does not make them worthless. It makes them a starting point rather than a verdict. What actually tends to sit behind a top-shelf designation:
- Bud structure and size. Larger, denser buds mostly come from the top of the plant, where light exposure is highest. Lower branches produce smaller, rounder nugs — often the same genetics, same cure, sold as smalls for less.
- Trim quality. Hand-trimmed flower keeps more trichome coverage than machine-trimmed. It also costs more in labour, and that cost lands on you.
- Cultivation method. Indoor and premium greenhouse growing gives tighter environmental control and a slower harvest-to-sale cycle. Sun-grown outdoor is cheaper to produce.
- Genetics and scarcity. Limited-run cultivars command more simply because there is less of them.
- Aroma. Strong, distinct terpene expression is the single most reliable sensory signal available to you at the counter, and it costs the grower real effort in cure and handling to preserve.
Notice what is not on that list: the THC percentage.
What the market actually charges for, versus what you experience
This is the part worth sitting with, because the two have come apart.
The same 2025 study estimated a THC elasticity of price of 0.17 — a 10% higher THC figure is associated with roughly 1.7% more per gram. Small per point, but it holds consistently across nearly four thousand dispensaries. Potency is priced.
The same study found limited evidence that dispensary-level characteristics mattered much at all — medical versus recreational, licence status, how many competitors sat nearby. Product THC level and item weight were the two most influential factors on price, full stop.
So the market has settled on potency as its main price signal. The trouble is that potency is a poor predictor of how a given jar will actually treat you, which we go into at length in the label guide. The percentage is easy to measure, easy to print, and easy to compare — so it became the price anchor, whether or not it deserves to be.
The practical consequence for your wallet: flower priced just below the potency thresholds the market anchors on is frequently the best value on the menu. A well-grown, well-cured jar in the low twenties with a loud terpene profile will often outperform a stripped high-thirties jar that costs half again as much. You are paying a premium for a number that does not do what the number implies.
Taxes, which are a bigger share than most people expect
Some of the difference between two dispensaries is not the flower at all. The same 2025 analysis found state tax rate at retail was positively associated with prices — the tax layer flows through to the shelf.
Tax rates change by legislation and by local ordinance, so treat everything below as the current structure rather than a permanent one. It is also part of why the same jar rings up differently at our California and Illinois stores.
California
The state cannabis excise tax is 15% of gross receipts on retail sales. It went to 19% on July 1, 2025 under a scheduled adjustment, then AB 564 rolled it back to 15% effective October 1, 2025 and holds it there through June 30, 2028.
On top of that sits state sales tax, with a 7.25% statewide base plus district taxes that vary by location, and many cities levy their own cannabis business tax as well.
One mechanical detail worth knowing, because it compounds: sales tax is applied to the price after the cannabis excise tax has been added. You are taxed on the tax.
Illinois
Illinois taxes by potency rather than a flat rate. The state cannabis excise runs at three tiers — flower at or under 35% THC, cannabis-infused products, and products above 35% THC each carry a different rate, rising with potency.
Local taxes then stack on top. In Chicago, general sales tax plus a City of Chicago cannabis retailers' occupation tax plus a Cook County one bring the total well above the state figure alone. We break the Chicago stack down in full, alongside the purchase limits, in how much weed you can buy in Chicago.
The structural point: Illinois deliberately taxes high-THC product harder. So in Illinois, chasing the highest percentage on the menu costs you twice — once in the shelf price, once in the tax.
Comparing two jars honestly
Given all of that, here is a sequence that works better than sorting by THC.
- Convert to price per gram before anything else. An eighth at one price and a quarter at another are not comparable until you divide. Most menus will not do this for you.
- Check the harvest or package date. Fresher flower is closer to what the lab measured. A cheaper recent jar frequently beats a pricier old one.
- Read the terpene panel if there is one, and use it to match products you have enjoyed before rather than to predict a mood. Where it came from is covered in our guide to how cannabis lab testing works.
- Compare within a tier, not across. The tier word tells you what the shop thinks. Price differences within one tier are where the real information sits.
- Ask what is on sale and why. Genuine overstock and end-of-run pricing is common and says nothing bad about the flower. So is a batch that tested a point lower than the grower hoped.
- Ask to smell it where the shop allows it. Aroma is the one quality signal you can assess yourself, for free, in about three seconds.
At Dr. Greenthumb's, every flower batch carries an accessible Certificate of Analysis, and staff will pull up the lab report at the counter if you ask for it. If a shop will not show you the paperwork behind a price, that is worth knowing before you pay it.
Sources and further reading
- Han and Shi, Multilevel Determinants of Cannabis Prices in Legal Markets, International Journal on Drug Policy, 2025 — the 710,588-product analysis behind the THC and weight elasticity figures
- Journal listing for the same study
- RAND, Variation in Cannabis Potency and Prices in a Newly Legal Market — hedonic price analysis of roughly 31 million Washington State purchases
- California Department of Tax and Fee Administration, cannabis tax revenue reporting — including that sales tax applies after the excise tax is added
- California Legislative Analyst's Office, cannabis tax revenue update — background on the excise rate and the repealed cultivation tax
Tax rates and figures above describe the position as of September 10, 2026. Excise rates change by legislation and local cannabis taxes change by ordinance, so confirm current rates with the relevant state agency before relying on them. This is general consumer information, not tax or legal advice.
