A long time ago, I hated decay... to a certain point I hate decay on Achaea, but I don't -mind- decay or the need to repair gear/armour/etc.
On Achaea, almost everything decays. Weapons, armour, clothes, enchantments... and unfortunately vials. Vials are the necessity for curing in Achaea. Those are where I hate decay, because it costs me on average 25000 gold every few (real) months to replace them.
You'd need to have a well balanced system to make sure you're not overspending resources and time to get back what you lose to decay. This can happen in Achaea with weapons and armour, since forging them gives variable stats, and people want the best you can muster out of them... which also drives up the cost of the finished good, on top of the cost of resources required to make them.
Namely steel in Achaea, which until recently was very limited and easy to buy out and deny other people. There was actually one player who kept buying all the available steel whenever it was repopulated, which caused a massive steel shortage and caused people to be unable to forge anything. This was fixed by increasing the amount of steel available in game ... and also shrubbing(essentially jailing them) the player involved, because they were bot-forging.