I have a fairly low end bike compared to many, a Quest Everest. This was Dick's Sporting Goods' house brand. I bought it second hand for $60.
I've had it for 6 years, and ridden it many thousands of miles. In that time, I've cleaned and lubed the bearings once a year, and replaced my cables, grip tape, and brake pads once.
EDIT: Oh, I also upgraded the tires and tubes after about 500 miles.