I am surprised to hear that about the Concept MM. For the money it is generally deemed a pretty good cartridge.

In your situation, I would call Needledoctor. Be prepared to share your system including what amp and phono stage you are using and what kind of music you listen to and they will recommend a cartridge that will suit your needs. Given that they have a 30 day return policy, they have a strong incentive to try and find a cartridge you will be happy with at your desired price point. I have bought a lot of stuff from them including two turntables and they have never tried the mindless upsell with me and I have faith that you will be happy with their advice.