I am more bothered by the fact you can see what the item has previously been selling for. I have no issue with competing with current sales - smart players don't bother undercutting because they know their item will still sell (particularly for popular items). I have seen material selling from 40k down to 15k and still selling again regularly at 35k (by selling I mean ACTUALLY being bought) so the undercutters ultimately missed out on a lot of money trying to deflate the market costs. If someone undercuts too much I buy it and resell it.