imo...somewhere along the way...the astros felt they could pretty much throw no-names into the closer role. they got less serious about seeking out highly qualified candidates for the closer role and went with players they already have to make up for it. i believe we are now paying the price for this incompetence. they didn't want to pay for a real closer and chose to pay with losses instead.
Every proven closer was unproven at some point. This team was going to be terrible this year no matter what. It is the perfect opportunity to throw Lopez and Melancon in the closers' role and see if either pans out so that, if/when they do become good in 2 or 3 years, they have a proven closer that's cheap rather than having to trust that team to an unproven closer or pay $10MM for a proven one. The whole point of seasons like this is to learn what you really have and give people the opportunity to win jobs. Going out and getting a Jose Valverde that we're not going to have in 2-3 years anyway just holds the team back. It's the failed philosophy they've used the last several years that got us into this situation in the first place.
A team should NEVER overpay for a closer, unless they are a bonafied contender and that is their only weakness. Every team has guys with a + arm in the minors that could easily be groomed to be a closer. Problem is, you don't know if they have the mental makeup until they get a chance. In the end, however, all teams would be much better suited to developing their closers from the farm system and keeping them for the cheap rather than overpaying.