This. The only two questions to ask when evaluating the retail price of a product are:

1) Is this product worth the asking price, and
2) Is this the best available price (after factoring in the non-tangibles like convenience, service, etc)?

If you have $3000 to spend on a bicycle frame, the frame in question is the frame you want, the frame isn't available cheaper in any convenient market, and you're certain you'll get $3000 worth of value out of the frame, why would you care if the seller got it for $30? Would you care if he got it for $4000 and was losing $1000 to sell it to you?

BB