Oh no the world is under attack by flying flaming buttocks! Only one hero stands a chance against them! But wait, even though the ass monsters are horrible and deadly, you still have to pay to save the world.
Take Diablo II for an example, in the rogue encampment, you have to PAY to be armed. For that Gheed person it's justified because he's a merchant and he's looking to move back to Luht Golhem when the stuff's over, but the people who LIVE there force you to pay to save their home.
It's confusing! It's like saying "That guy's about to shoot me dead, but in order to save me you have to pay five dollars for the rights to".
So anyways, why the hell would you have to pay to get these weapons, if you need them to save the merchant's life?