One of the bigger problems i've noticed with a lot of leather furniture is that you can't easily re-stuff it. I hate saggy seats. Sure you can get hardwood frame & webbing instead of springs, but there's often nothing you can do about the eventual depressions in the cushions. Depending on the firmness of the foams that are used, this can be more or less of a problem. The next time i go shopping for a leather couch, I will make sure that the cushions can be removed without tearing the whole couch apart.
If you had not had price as your priority when you bought the pices, you would have gotten heavier, denser foam which would last a lot longer. After all, at the end of the day, the cheapest is really the most expensive.