It's not going to happen on "inexpensive." Quality comes from "custom made." When I'm working on a decent schedule and a workable budget if I need a specific sound I go to great lengths to create it if at all possible. If I need to go into the field I rent the appropriate sound kit; I have a decent selection of mics, but I'll also rent mics if I need to. I also do extensive Foley work.
What sounds are you looking for that you have been unable to find anything satisfying? What libraries have you auditioned? There are quite a few that I'm bored with, but there's a lot of quality out there if you take the time to listen.
BTW, I use sounds from libraries, but there is never one sound that will do the job; it will be carefully selected layers and/or sequences of sounds. I spend a lot of time finding them and spend what I must to acquire them.
