You forgot "These people aren't really bright, are they?"
Seriously, man. Half-ruin your game experience just to get that next uber l33t sword? I mean, in games with any kind of economy, this makes no sense. Because some people want instant gratification, it makes it harder for the next person to buy what they'd like. Which increases frustration with that person. Which makes it more likely they'd buy it that way, too.
Ruin might be just a little bit too strong, it unbalances the ingame economy by allowing other means of buying items which could never really be solved even if tryed. Where there is money, there is a way.