Thorens TD 316 Worth Saving?

I bought this a couple of years came with a Thorens TD 21 tonearm and a Shure ML140HE cartridge. The stylus is Shure, but I didn't see any model or numbers. It has a thick Stinger cable coming out of it, aqua in color This turntable does not have auto return. I know it works, I heard it play but the skating was so bad I put it away and kind of gave up on it. I have ordered the string and weight for the skating.

Do cartridges lose quality with age and what would be a good stylus in the $200 range?

I've read that the 316 was not Thorens's best work. It needs a dust cover, and most likely a stylus. Is this turntable worth putting more money in to?
I had a 318 once. Not terrible but not great. A bit dull and leaden. Try this in it.