I suggest the following as a solution to two problems, namely (1) inflation and (2) the so-called pushing:

When an item is auctioned, the seller receives 90% of the price paid, and 10% goes to the auction house, i.e. disappears from the game.

Thus, when there is a case of pushing, 20% of the too-high purchase price is removed: 10% on the purchase of the high-level item, and another 10% when the seller buys a low-level item from the purchaser to return the Thaler.

After a few rounds of doing that, the big pile of Thaler that was previously just going around in a circle will be significantly reduced.