Leo, i've thought of way to free up inventory and make some non obtainable items available. In the class coliseum make a shop. In this shop all items for sale are worth coliseum points. You obtain coliseum points by beating mobs in coliseum and can trade in class items for points. For instance can trade in power up potion I for 1 point, power up potion II for 5 points, power up potion III for 10 points, class enhancement stones I, II & III can be traded in for points as well. The shop should sell all types of power up potions (yes power up power up potion IV) and class weapons.