Need help buying a used turntable for $500

OK gang,
My father has left me a vintage collection of Jazz albums and I have my own collection of 70 & 80's Rock music. I have a Denon 3802 receiver which is only sending 110w per channel to a pair of B & W 604 towers. So I am looking for a turntable I can afford and still get the best possible sound.

I have been looking at used Thorens, Rega, Project, & Lencos but it is impossible to tell what model and year are a good value. Can anyone help suggest the criteria I should use for selecting a suitable turnable and offer some models to pursue?

I would greatly appreciate your advise.
Thanks