Back when we had a trailer on the midway, one vendor averaged $90/k an event. Of course they were always given the premier spot and allowed to sell items that other teams couldn't.
Several trailers (around 8) averaged between $15 - $30/K per event. Your driver is important, but your marketing hook is more important. Constant new and edgy merchandise always pushed sales. Many times the merchandise name was a bigger selling point than the team or driver, such as Nitrofish or RaceGirl.
Teams with just car/driver merchandise usually struggled to gross $5/k an event.
Bod is a good person and his family and team are top notch. I wish them all the best in achieving the goals they have set for themselves.
An apparel sponsorship usually only supplements support of a team, seldom can it carry the main load. But when managing a team you are looking for all the income you can get from every source you can imagine.