This is pretty good start, but you would have to start adding the nickle and dimes from this point. Cost of closing the courses, cost of renting the courses, cost of renting the picnic shelter, cost of event insurance, cost of the porta potty, cost of printing, cost of artwork, cost of trophies, cost of OB paint. Amortized costs of tents, tables, practice baskets, banners, brooms, garden tools, fence posts, fence post hammer tool, coolers and tons of tiny items worth little but fill the TD box with all the tools needed. Not to mention the capital always tied up in merch.
I am not saying someone could not make a living from a TD/disc store enterprise. I just think it would be a meager living.