Mini Monitors under $500 used

I have a small room 10x10x8 that Im using as a den. Have a Nad 326bee and Marantz 6250 cd, what would you recommend for speakers? Detail, sound stage, and resolution are important to me.
thank you for answering
also just read about Silver Minuet supreme and Harbeth (which are much more expensive).
Second the Usher S-520. It's a great speaker for the price and size.

In that price range, I'm also a fan of the PSB Stratus Mini's.

I believe nad and psb share same distribution and demo often...Fwiw...I was in a funky Thai restaurant with a amazing dj...I was so captivated by the sound I checked out the speakers...mid level psb...
I have listened to the NHT Super Zero, PSB alpha B1, Silverline Minuet, Paradigm mini Monotors. So far the Minuets and Mini Mononitors sound the best for me. The Minuets are smaller and have a very large sound. The Mini Monitors have this great 3 d sound. Hard to pick right now. My room is small 11x10 with a bed
Thanks for all your suggestions. Its hard to obtain some of the speakers used to audition. I want to try the ushers , Triangle, Rega RS1 and Dali Zensor 1.