Stainless steel is, umm, more expensive than mild steel. Sure, it doesn’t rust which is great but when we first made the switch, we had a shop full of mild steel that we did away with it AND we ate the price difference because we didn’t want to roll over the increased cost to our players.
Why? THE SOUND, BABY. You tap a sheet of stainless and it goes “ringggggg” and you tap a sheet of mild and it goes “thud”.