Regarding whether expenses of operating a marijuana dispensary/shop are deductible.
MARTIN OLIVE, Petitioner v. COMMISSIONER OF INTERNAL REVENUE, Respondent
Expenses incidental to the primary business of selling pot, such as yoga classes, are also not allowed.
But cost of goods sold, which is like a deduction, is allowed because it is technically not a deduction.
A possible effect of the ruling is to make the cost of medical marijuana more expensive to compensate for the absence of deductions. They might also restructure their businesses so that the incidental stuff, like yoga classes, are operated as a truly separate business.
Anyway, the dispensary was closed down long ago as it was too close to a playground. Taxes plus accuracy related penalties (which has nothing to do with math errors) are still due.