There's a lot of pot in Oregon; more than consumers can smoke. The surplus makes the state a very cheap place to be a stoner.

According to a study from the Oxford Treatment Center, a drug-addiction center, Oregon is still the cheapest place in the nation to buy weed.

Data show that an ounce of high quality weed here costs $210.75, less than Washington, where an ounce is $232.90, and Colorado, where it's $245.74. Washington D.C. is the most expensive state to buy pot—there residents pay roughly $597.88 per ounce for high quality cannabis.

David Cusick, a spokesperson for the center, says this is the first year the study has been conducted so there is not equivalent data from a year ago to compare.

Last August, WW reported, prices for wholesale outdoor-grown Oregon cannabis hit an all time low of $398 per pound. According to Cannabis Benchmarks, which monitors industry prices nationwide, the current wholesale price for a pound of outdoor grown pot has decreased to $381.23.

Oxford Treatment Center's study shows that the average price for a joint is also lowest in Oregon, at $4.91 per joint. The national average is $7.59, and the most expensive state to light up is District of Columbia, where a joint is $13.92.

So happy 4/20, Oregon. Enjoy your bargain high.