My Herron Audio monoblocks had to go back to Keith for some service and updates and I picked up a pair of used PS Audio Stellar M700 monoblocks to hold me over. I was not expecting them to be as good as my Herron M1s or the Rogue Audio M180 tube monoblocks I had before, but... they are really good. They're dynamic, detailed, but a little on the warmish side of neutral. No rolled off top end or harshness that are some of the things people commonly complain about with Class D amps. They are supposed to be "voiced" to sound like tube amps, and I think they've come close to that goal. You can find a pair in your price range.
There are a lot of options in your price range, especially used. Someone has a Parasound A21 listed, that might be worth a look.