Best turntable for 500?

Doesn't Rega have a RP1 at 445.00 fitted with a Ortofon MM cart. If she needs a phono stage you 55.00 toward one in the 500.00 budget.

Hard to imagine an older lady that would be thrilled with a manual TT.
If it was my mom I'd look for a cherry used Sansui or Sony semi-auto DD.the better Sansuis in particular are probaly the best looking tables ever made.
In 40 years in Audio I've been thru hundreds of pieces of gear,the only thing my wife ever fell in love with was a jet-black Sansui 929.

B & O's are my favorite!! There are many beautiful units on Audiogon from time to time!!