Sorta depends on your maintenance schedule and what you're shooting and how much shooting you do.
There's some that replace springs every 5000 rds or so, barrels when they need it, other bits and pieces as need be.
Some guys shoot powder puff reloads, others like hot barn burners.
I've only met a couple of local shooters who are serious and told me they shoot 500 rds every week, but compared to the big boys (who might get their guns from the factory they represent) I suppose 500 rds a week isn't too much.
I have read about service life of 150,000 rds, tho' I'll be darned if I can remember where I read that. If you could afford to shoot 500 rds each week that'd give you, what? 300 weeks or approx 5.8 years of hard use?
When to retire it? When the frame starts showing signs of stress cracks I'd think.