I think you've forgotten to mention the actual reason why the prices are so low.
People buy the items and then try and sell them of course at a lower price than what's already listed by other players.

The real issue, in my opinion, is too many people trying to sell items and not enough people buying the items. It's the same issue in the steam market for CS:GO items. Eventually, the prices go down and down and down for most items because the people that want to keep the item doesn't match the amount of people that want to sell their item for profit or money and each time the item is listed, it's usually at a lower price than the ones already listed which causes the prices to go down.

You can't really stop the prices from going down. You can get rid of over inflated items yea, but eventually, the prices will go down by themselves again due to the marketing aspect. This of course is a problem for those like you, who buy tons and tons of the same item to try and keep the prices for that item somewhat high but then a bunch of people come in and bring the prices back down.