My Luggageworks Stealth 22 has been going strong for a couple years now with only some scratches on the corners, but it's definitely an investment. The 2 problems with it are the lack of a handle on the bottom, and it's pretty high empty weight.

For about 18 months, I used a Delsey roller around the $125 price range. I forget the model name, but it was a 22". It was a very decent bag and has a lot of life left in it, it just isn't a 300+ day/year bag anymore. I'd say without too much abuse, it could go about 600 days. If you travel 5 days/month, I'd say the bag would last close to 10 years.