The short answer
The same eighth of flower can cost twice as much depending on which state you buy it in, and state law is the reason. Three levers do most of the work: taxes stacked on top of the shelf price, the number of licensed growers competing for your dollar, and whether you hold a medical card. In states that still criminalize possession, the cost shows up as fines and court fees instead of a receipt.
Cannabis Laws by State: Possession Limits Guide
Taxes are the largest single add-on
Most legal states charge an excise tax separate from ordinary sales tax. Washington runs 37% at retail. Illinois uses a tiered rate of 10% to 25% based on THC content, then applies sales tax on top. California charges 15% excise plus local taxes that can push the total past 30% in some cities. Colorado pairs a 15% excise with a 15% retail marijuana sales tax. Oregon charges 17% with no general sales tax. Massachusetts adds 10.75% excise to the 6.25% sales tax.
The stacking is what catches people off guard. A $40 eighth in a 37% excise state lands near $55 before sales tax and closer to $60 after it. Rates change, so check the state revenue department rather than a dispensary menu from last year.
License limits decide the shelf price
Oregon and Washington license far more producers than their populations can consume. Wholesale flower there has traded for a fraction of what it fetches in states with tight license counts, and retail prices follow wholesale down. States that cap licenses, require growers to also run their own stores, or roll out retail at a crawl keep supply short. Florida's medical program, built on a handful of vertically integrated operators, ran expensive for years for exactly that reason.
Local bans matter too. When a county blocks retail, buyers drive to the nearest open town, and the shops that stay open face less competition on price.
Medical cards change the math
Several states tax medical cannabis at a lower rate or not at all. Colorado exempts medical from the special sales tax. Illinois charges medical patients 1% instead of 10% to 25%. Massachusetts exempts medical purchases from both the excise and the sales tax. A card usually runs $75 to $200 for the doctor visit plus a state fee, so it only pays off if you buy regularly and your state offers a real break.
Where the same product costs the most and least
Markets with years of oversupply have seen mid-grade flower under $5 a gram. Restricted markets have sold eighths at $60 and up. Alaska stays high because of transport costs and limited cultivation. New Jersey was expensive through its first years of adult-use sales. Michigan and Oregon have landed on the cheap end. None of this is fixed; a state that adds licenses or cuts taxes can move prices within a year.
What illegal states cost you
Fines replace receipts. Texas treats possession of two ounces or less as a Class B misdemeanor, with up to 180 days in jail and a $2,000 fine, though several large cities have cite-and-release policies. Even a misdemeanor can follow you into housing applications, job screens, and student aid. Add court costs, lawyer fees, and the price of a drug test, and the sticker price of a legal eighth starts looking like a bargain.
What to check before you buy
- Your state's excise rate and whether the city or county adds its own tax.
- Whether the shop is medical only, adult use, or both, since the tax differs.
- The all-in price per milligram of THC, not the price per gram of flower.
- Card eligibility and the annual fee if you buy more than a few times a month.
- Transport rules. Carrying cannabis across state lines is illegal under federal law no matter what both states allow.