Depends where you are I guess. I know guys who can't afford to live on instructing alone (getting paid per flying hour with low student numbers) and have primary incomes at fast food joints and other jobs. On the other hand I know guys who are on very nice pay checks as far as GA is concerned.
Depends on what organisation you are at as well. There are still too many instructors for the job positions at the moment in NZ at least. A couple of my mates got made redundant not long ago so the GA industry for now is still in a sort of a slump.