great idea, but this is what i think
They should set up a terminal where either:
1) a person unlocks weapons/armour as they level up, and can rent them for set price per hour or
2) a player puts an item in the rent terminal, where players can pick up the item with a fee, for a period of time restricted by the owner of the weapon or gear. This will help with the inflation of money in SL and will act as a type of investment income, providing people with a easier way to earn money to cope with the rising prices of weapons, gear and vanity