I while back bought a lot of about 40 chips from a seller with great feedback (note: he was not a chip collector, just had some chips he picked up at an estate sale). I picked up the chips in an auction very cheap and they were worth considerably more than I paid for them. One chip was worth double what I paid for the whole lot. The seller had the auction shipping price at less than 4.00 so when I paid him, I added a few dollars to my payment with an explanation that it would cost him more than he estimated to ship them to me across the country. He refunded my overpayment and told me that he couldn't accept my additional payment and thank you anyway. It cost him half the price I paid for the chips to ship them to me. I couldn't understand why he wouldn't allow me to cover the whole shipping costs as I totally volunteered it up but I was very impressed that he stood by his listing.