Many pot head characters have found their way to the audiences over the years; Cheech and Ching, Bill and Ted, Wayne and Garth (though very subtle about it), even Shaggy and Scooby (again very subtle about it).
So the the pot character comedy genre seams rather viable. Potentially in this case, because more countries are now ratifying legalization around the world, this concept has a timely relevance.

The logline has a few problems in it though here are a few problems with the logline’s technicalities and conventions;

Firstly the MC is referred to twice with different descriptions “…a dishonest pot-dealer…” and “…the de-motivated…”. This can be confusing so best to stick to one description for the reader to follow.

secondly it is too long and needs to be re written with more economy, there are too many adjectives and actions that could be done without.

Secondly about the story;
If the MC is a drug dealer and a dishonest person who’s goal is financial gain I would find it very hard to empathize with him or her. I think a different character flaw would serve better here and a better goal one that perhaps serves a greater cause for the community at large (from the MC’s point of view).

According to the current draft the inciting incident is receiving of the bill not the legalization. The first event that needs to be mentioned and there after focused on is the the bill.
However this raises too many questions that put the premise in doubt. Laws are not passed retrospectively and here the logline implies that the former illegal activities the drug dealer undertook had been monitored accurately enough by the authorities for a tax office to generate statements about his activities.
If so wouldn’t he had been arrested before the legalization? Also aren’t most if not all drug deals paid for in cash how would a tax office monitor his income?

I think the bigger and and more logical inciting incident is the legalization this would help solve these problems.

Hope this helps.