the dealer might want to remember what he paid for a table when deciding how much to sell it for

Perhaps, but I doubt it. It becomes more important later--when it's time to re-stock. That's whent the dealer should think, "Let's see, I bought the last table for $50 and sold it for $40. This time I won't buy for more than $50."

In other words, it should affect the dealer's bargaining with her own dealer, not with the buyer.

Edit: I changed the last word in the previous sentence from "seller" to "buyer."