There are thousands of items in this game. Hundreds that aren’t for sale with any frequency due to low worth. Even that system combined wouldn’t make a big difference. In fact, all it would do would be to obscure folks doing it so people wouldn’t be able to even try to interrupt it.

“What’s not on the market at all right now? +2 frugality moar file? Okay, folks grind it for a bit and lets go toss up 10 of them. They’ll show up between 1 and 3 hours from now. Bid on them.”

It’d be only luck if someone else managed to put up the same previously not worthwhile item at the same time as them.