I have heard the V3's with Pass XA100's, Hovland Radia, Bryston 7BSST, Chord Monoblocks ($26,000; can't remember model number) and Rowland M312 in the same room. The Pass Amps were the best to my ear...excellent synergy with V's. May be a tad out of your price range used. Rowland M312 was a close 2nd, perhaps lacking in bass slam/depth compared to Pass amp....not by a wide margin. Bryston Monoblocks were a bit thin or perhaps lacked the warmth of the Pass/Rowland variety. The Hovaland Radia was too polite across the frequency spectrum for my tastes.
Amp recommendation in the $6000 range
After being out of the hobby for a few years I'm now looking for a used amp in the 6K range to drive my Magico V3, I had interest in a Pass Labs X350.5 but with this model out for 10 years I don't think it would be a wise investment. I'm looking mainly at solid state stereo amps but is open to tubes and other ideas. My other requirement is I do like power, so at least 150 watt for tube, 200 watt for SS. Thanks in advanced.