What is a reasonable price for a 500 brick of 22 ammo?
I would say that's a question best answered by the buyer.
Both Buyer and Seller often have very different ideas of what constitutes a reasonable price.
Seller usually wants to recover costs and make a profit, Buyer often thinks a reasonable price is one at which the seller would take a loss. Neither is necessarily wrong from their unique points of view.
It is only when Buyer and Seller come to an agreement that a transaction can take place.