[Formerly YB-2]

The Marantz 6100 is not what one would consider one of the better TT/TA rigs of the era. This was the time when Japanese direct-drive turntables were king. Sony, Denon, Kenwood and the Mitsubishi linear tracking TTs were all excellent pieces, as were the Dual 1219 or even better, a 1229 if she would prefer a changer. Carl's Kenwood might be a better choice if it is DD. Belt-drives back then were pretty much the 'bargain' end of the lines. eBay used to be full of these excellent Japanese DD TTs, but the resurgence of the LP has thinned the pickings.

You might peruse the Barter Town section on the AudioKarma forum. It often has a number of vintage TTs listed. The "Turntable" section on AK is primarily made up of us vintage TT folks. Like FM tuners & receivers, that was truly the era when the LP & FM radio were as good as one could get.

However, if it were me, I would look closely at the Rega Planar 1. You can get one new with an installed cartridge for $450. Two possible drawbacks might be the fact it is a manual TT/TA and does not come with a dust cover (which a silk scarf replaces nicely). Any of the older TT/TA have a fair amount of mechanical & electrical/electronic complexity. They can be "fiddley". The Rega could not be more simple and straight-forward.