Marijuana sales up again The Oklahoma Tax Commission reported May figures for medical marijuana tax collections, and the numbers show sales increased again compared to the previous month. According to the data, Oklahomans purchased approximately $79 million worth of marijuana products that month, an increase of $5 million from the previous record. A year ago, sales were less than half what they are now. The Tax Commission reported it collected $12.5 million in taxes from May sales, which include the 7% medical marijuana tax plus state and local sales tax. Researching free speech The John S.