Okay, the RPG has a few item shortages, and I noticed that alot of people have tons of items they don't use or need. So, if you are one of those people, sell all of your old items/weapons/etc. that you no longer use or need. It keeps the shops in stock for new users. There is no reason to have that many items in your inventory, especially when you don't even use them. When you upgrade, trade in your old ones for the new ones. It keeps things fair for everyone else.