A big part of what sucks? So many of these guys could be acquired via free agency, costing no prospects and at most a draft pick
Yu Darvish, Annibal Sanchez, Zack Grienke, etc al
If you later have to trade to acquire guys like this, you end paying the big $ on their contracts anyway, and have to pay in prospects too. The only upside is you have fewer years on big $, but that's not even always a good thing for a guy going in to his late 30's while you still have him, as you may have missed his best years.
Edit: For the record I would not have been on board with the Grienke contract - no way no how