Same here. I buy cassettes or chains well more often than tubes. My tubes might last longer than my tires.
Heck yeah, I'll go through at least 2 sets of tires before a tube is remotely considered to be replaced. I don't even buy cassettes and chains that often, my chains last an average of 10,000 miles and the cassette will last 3 times longer than the chain. My touring bike is supposed to go through chains faster, but I have about 1,500 miles of loaded riding on it and so far it's showing no wear on my chain checker, and supposedly on loaded riding they get about 3 to 4 thousand miles on a chain, I'm waiting to see on that one.