Wool socks, wool toe
Wool socks, wool toe socks.
Maybe material and tools for people who want to make their own sandals (I know the profit margin on these would be minimal but it may make customers happy). It would be neat to have a real store where to see and touch samples of Lunas, invisible shoes, etc. Even if those companies don't use retailers it would be great to have a place to see their product before placing an order.
I ran in homemade sandals+wool socks last winter and plan to do the same this winter except for a few wet snowy days when scuba boots might be warmer, and I'll wear my Merrell Pace Gloves when traction is needed which is rarely the case here since it's so flat.
The usual winter gear is not specific to barefoot/minshod runners: pants, hats, gloves, jacket.
For all seasons:
Compression sleeves, cool BRS stickers and temporary tatoos, RoadId and other ways to attach timimg chips (dog collars, velcro brands, neoprene bands, etc).
A selection of camel backs. I don't personnaly own or use one but I know people use them without the bladder to carry their shoes. Handhelds, hydration belts.
Nail polish. It makes me run better ;-)