Are 500 hours too many for a used hi-end cartridge?

Pertaining to my situation of being a “tight budget audiophile” (if there is such a thing):   If one has an inexpensive turntable with the stock tonearm — in my case a Denon DP-300F with an Ortofon 2M Red cartridge — does it make sense to put a more expensive, higher quality cartridge on that tonearm?

And, given that the records likely to be played on that turntable are 40-60 years old and played on equipment of lesser quality than the Denon . . . like a Penncrest (JC Penney) portable record player with the included ceramic cartridge from 1965 . . does it make sense to play them using a higher quality modern cartridge than the Ortofon 2M Red?

@chakster, I didn’t know I could fit a better stylus on the Red.  How is that listed?  Do I simply search for a replacement stylus for that cartridge and choose from among those listed?  

I would think a big issue with how these old records were played would be the heavier tracking force, that wouldn’t be adjustable on the cheaper record players back then.  Also, I didn’t hear about cleaning records until the early 70’s, when I got my first turntable and was reading about audio equipment.  I recall getting brand new records with a few pops mixed in (mostly just heard on quiet passages), which we thought was just part of the medium at the time.  And, of course, who thought of replacing a needle after so many hours of playing — those things lasted the life on the player, right!  😲

I have come across a few old records now that still sound muffled when I play them.  Do you think further cleaning would help, or are the grooves likely permanently damaged and no amount of cleaning would help?  Thanks for the info.