If the prices of the items at shop drop, that means the players are going to sell them cheaper. For example, if the gods dropped to 500 the players will sell them for less in order to make money because why would you buy God apples from a player for 500 when you can already get it from shop? So basically dropping the prices of items at shop will ruin the economy and making it harder for players to make money. Really no point of changing the price since you will always find cheaper prices from players than shops
Also making items super cheap allows players buy a lot of these stuffs in bulk easily which is a bit too OP in my opinion