Also consider that I may find a $5 chip for 35 cents, so you can't assume that every chip was purchased at face.

On the other side, some 25c chip, may have been purchased for $35 and sold for $10, which you have no way of knowing.

I think you've stepped into something here and it's not easy to figure out what people are making or losing, without all the data.

As I've written before, if I could buy $1 chips and sell them for $3 each, shipping included, I'd be packing and shipping all day long. Same for $5 chips at $7.00 "shipping included". (no I would NOT combine shipping, since it's already free!)