Good, warm, musical, under $500 used monitor

I've been searching for the perfect inexpensive monitor, and have way too many options. You know, I keep thinking I have it nailed down, then I'll find something I might like better. I like a warm, musical tone, but my system is bright, and I have a small room. I'd prefer an engaging sound over hearing every last detail. Had been considering a used Sonus Faber Concertino, but it is above my $$ range. That is the sort of tone I'm going for, though. I'll be getting a sub as well, so I'm not concerned about the bottom octave (although which sub will depend on which speakers, of course).

I'll consider new, as long as it's in the price range.

What's the perfect speaker? Helppppp!!!!!!
Can't say enough about the ATC SCM7s at $1100/pr. May well be the sound you are looking for.
I went *Chinese* <> Swans M1, which were later modded by Dan Wright. Will go head to head w/ anything ~ 3K, no sweat. I saw a pair w/ stands going for $500 here...
JM Reynaud Twins. Amazing for the price (about 550 used). Every night when listening to music I am blown away anew.
The perfect speaker does not exist no matter what the price, IMO. That said, I like the PSB Stratus Minis-- bass down to near 40 HZ, detailed but non-fatiguing, and can be warm depending on speakers cables and the rest of the system. They should be available used under $500. Good Luck. Craig
Spica TC-60's, usually $400-450 when available.
proac tablettes 500 or under used...great sound great imaging.
If you go the PSB route, be prepared to give them a lot of power, they need it. Along that same line would be the Magnepan MMG. Can be had new shipped to your door for 550, less if you buy used. They need power also, but can sound good if set up right.
Soliloquy 5.0. Warm and musical esp with tubes.
2nd the JM Reynaud or you could try Spendors.
If your system is bright may be your electronics too.