My 500 combo is about 20 years old. It cost about 225-250 then as I recall. It is pretty beat, but still functions flawlessly. It comes completely apart with the removal of one pin. There are about 5 parts, not including the trigger. I can clean everything and reassemble in about 5 minutes.
My buddy just used it in Ohio and shot a nice buck with the smoothbore/rifle sight barrel. I've shot deer, turkey, rabbit, a few ducks, grouse, woodc ock, pheasant, etc. with the barrels that came with the combo. I kill turkeys out to 35 yds easily with a newer accuchoke barrel using the standard full choke. Cheap and reliable, and you don't mind the inevitable nicks and dings. What else do you want for a hunting shotgun?
The same could probably be said about the 870. I have heard some bad things about recent 870 chambers being rough and ejection/jamming problems. There were some recent 500s that I just didn't care for the forestock design or the stock color in general.