You need something done, and you go with a cheap vendor. It seems straightforward from your point of view, and eventually you get a result you are happy with. You think you've made the better choice, and you saved some money. You may have even gotten some praise, or a promotion even.
Eventually, some cracks start to appear which you need fixed, but the vendor has disappeared off the face of the Earth, and you need to find someone else to take over. Who knew the bottom of the barrel pricing strategy is a tough one to pull off.
You scour the land for a vendor willing to inherit a project. You succeed (now, this deserves a promotion, or at least some praise).
Only thing is, they tell you it's crap and it needs a ton more work to be made well again. It needs to be brought up to their standards, otherwise they won't even bother. Oh, and they are charging you a premium because they are basically going to be doing shitwork for a while.
You realize you have just delayed the payment of the “premium” option. Plus you've lost time, nerves, and as you have now learned: even more money than it would have cost to be done well in the first place.