Archie, please help me to understand...

Your price guide says "estimated retail prices from established dealers for chips .. in excellent condition".

Then you list the value of a RES-1 as $25-$50. That's a huge spread for a chip from a dealer "in excellent condition" and to make matters worse, you offer this chip for sale on your site at $75.

I'm more than a little lost here. The value of this chip (in excellent condition) seems to be all over the map and this is just one example.