Thanks for picking this manga up!
@Owyn
Durandal requires 63 points as somebody else mentioned, he can dismiss the weapon at any time to free up those points and allocate them to something more useful, like faster levelling. However, if the sword were to be stolen from him, he will become unable to dismiss it and regain the points. Hence why he is somewhat paranoid about having it out in public.
What makes Durandal such a valuable weapon? Its attack power and enchantments. It has health and mana restoration in addition to cast interruption. In this word an item with two enchantments is considered to be a weapon worthy of heroes. 3 of them is basically legendary. Why?
Because of how enchanting work, not only do you need to acquire material to gain specific enchantment, but you also need to get lucky when enchanting the item. If the enchantment fails, the item will turn into raw material and enchantment material will perish.