What is the replacement cost of the oranges they had in inventory? Should the stores have waited to raise prices to market price until they sold out their inventory? Then what happens to them if after they buy replacement inventory the market price comes back down?
"What is the replacement cost of the oranges they had in inventory?" That is not relevant, the fact is they raised the price to the new price knowing all along they would make a windfall profit on their current stock which they paid less for.