The real value is what someone is willing to pay for it. Ebay sets the market as far as I'm concerned -- what you hope for is a chance to find someone wanting to buy your chip(s) above what they can get it for on ebay. Not sure why they would...

For that premium, the chip/condition combo better be hard to find, or find collector who stays away from ebay, and is willing to spend for what he/she wants when he/she wants it.

Like the TCR 'O' rated chip below. What is it worth?

Ever thought of an auction? Sure there are some dealers who would handle for a cut. Dealers at shows also seem to get decent prices -- maybe have someone sell on contingency.

Just some thoughts. Good luck.