Whats the best used tuner for under 1000

Lpquick is right! I still use my 12 yr old NAD Monitor Series tuner, as it was clearly one of the best of its era (and far better than their current tuners), but my Magnum Dynalab MD100 is profoundly more realistic in its portrayal.
Live feeds are eerily good. Balance is a little lean because the top octave is so clean, so I use a Harm Tech Truthlink XLR with fine results. NEW ones can be had around $1200, used older Etudes and 90s $600-$1000.

Mcintosh mr-71 (vintage, tube) sounds gorgeous and is sensitive too.

Spend less than that about 650 and get a Marantz St17
very good tuner dual antenna input, digital , flywheel tuning nice small package. I ahd one and traded it in on a McIntosh M85 and it was not worth the extra money.

I deal in vintage tuners and highly recommend the Macintosh tuners. The two best are the MR-78 and the MR-80. The sonics are world class for any component.

If you like tube glow, the MR-71 is the best. They are a little lower build quality than the 78 and 80. I keep one of those in my all-tube Cary 300SEI system. It is better built and sounding than the MR67.

You should be able to find any of these tuners for 1K or less. The MR78 and 80 will likely be a little less than perfect cosmetically for that price.

No question about it, buy a McIntosh MR78.