[Exhibitman]

Don't offer anything. Ask the dealer to make the offer. Make him bid against himself. You will be surprised how many dealers will knock off a substantial sum from the sticker price, especially if prices on the card are stagnant and the card is relatively easy to find. I like to go with "what is the absolute lowest price you will accept for this card?" See what happens. Better than dickering.

That said, don't expect much movement on a card that is iconic, soaring in price or a rare one. No need to discount those. Last show I did some guy wanted me to discount a rare boxing card. No thanks. I can't just find another one on eBay. I think many dealers will hold a genuinely rare card until they get their price. I know I will.