Here's a nice pair of Joseph Audio Pulsars in your price range that should be a significant upgrade over your already excellent Boxers. Best of luck.
https://tmraudio.com/speakers/bookshelf-monitors/joseph-audio-pulsar-bookshelf-speakers-gloss-black-...
https://tmraudio.com/speakers/bookshelf-monitors/joseph-audio-pulsar-bookshelf-speakers-gloss-black-...