I've been looking for the best IEM for $50 and so far, the Carbo Basso and Tenore are it!
The more earphones I compare to the Zero Audio Carbo Tenore (with MEElectronics M6 double flange tips) the more I realize how incredible they are. They hit hard, they go deep, they're airy, detailed, clear, engaging, and draw you in. My only beef with them was that they sometimes could use a little more bass. I used the EQ on my computer to VERY SLIGHTLY bump up 31hz, 62hz, and 16k (for a little more sizzle) and WOW, they're amazing.
Nothing I've compared to them can compare, A161P, S500, nothing in my sig.
If you haven't tried the Carbo Tenore (even better with MEElectronics M6 double flange tips), give them a try!
The Carbo Basso is equally impressive after I EQ to my tastes (lower the bass, raise the treble).