On Wednesday, Sean Azzariti became the first person to buy marijuana for non-medical purposes when he stepped into a store in Denver. He paid $40 for 3.5 grams of Bubba Kush, and another $9.28 for a few pot-laced chocolate truffles (My GovBeat colleague Niraj Chokshi was there). All around Colorado, people lined up for hours to get their hands on the first legal weed in the country.

Soon, residents of Washington state will be able to follow suit. And now that the flood gates are open, marijuana legalization legislation is likely to come up in state capitals across the country.

But while marijuana for recreational use is still illegal in 48 states and the District of Columbia, that doesn’t mean there aren’t buyers and sellers. An interesting set of data, compiled by PriceOfWeed.com, shows high-quality marijuana is most expensive in North Dakota, and in several Mid-Atlantic states.

The Web site has been soliciting input from marijuana purchasers, anonymously, for several years. They ask where a purchaser lives, and how much they paid for the drug. Mapmaker Renzo Lucioni crunched the data and found the cost of high-quality marijuana is consistently lowest on the West Coast.

States where users report the highest cost of high-quality marijuana include Wyoming, Iowa, Oklahoma, Louisiana, Virginia, West Virginia, Maryland, Pennsylvania and New Hampshire.

Check out his complete findings here.