Also his shirt was stained and he looked kind of unkempt.   

It would look like this...T-Shirt Co: We are Selling Yellow Shirts.Customers: We don't like Yellow Shirts.

No different than if you ran a T-shirt business. 

May be worth a meeting and a conversation to sound them out.Edit for a fun story:I worked with this guy who was super stoked on 420, had "legalize it" stickers all over his car, wore Bob Marley shirts, stopped work every day at 4:20 to take a hit, etc.

Guru in all your endeavors...shave, change your shirt once in a while ( YT videos) and smile.

Unless you really know what you are doing, you can lose your shirt.

If you are buying to flip, could you rent if you got stuck with it without losing your shirt?

They're going to lose their shirt and we will never hear from them again. 

I'm pretty sure that's why the shop down the street also hired a manager to sell their tee shirts. 

Learning by doing and teaching is my philosophy, and unfortunately, this system did not facilitate that process.I truly wanted this endeavor to succeed and even expressed my gratitude by sending Fire Station shirts to the Flip System crew.