What is a typical life span of a stylus or cartrid

It lasts until it's worn out which depends on use/abuse.

If it's a reputable dealer, it should have been taken care of properly. However, it it was demo'd by a number of customers not in the presence of the dealer, it could have been abused a bit. Personally, I'd pay the $70 and get a new one. It avoids problems.

If it were me(now that I know the price range): I'd buy a new unit(12% isn't much of a discount for used/demo gear). Still- I've never bought a cartridge(in the past 30+ years) without first inspecting the stylus, via a microscope. I've seen a number that were mis-aligned when mounted on the cantilever(new in the box), in that time. A lot depends on your trust of the dealer, and how much the $70 means to you. Can you believe his assessment of the time on the unit? Does he let cutomers mistreat his equipment?(unlikely, but possible). Like I said though- You should still audition the unit with your phono stage/pre-amp, before purchasing(new or demo unit).

I don't think he is discounting the table enough for a demo price. 20% off retail might be considered typical demo price. Perhaps the low cost of this table warrants a lower discount, not sure about that. In this case I would buy new. $70.00 hardly buys dinner.

Good call Viridian. If the new stylus is less than $70, that would seem the way to go.