Originally Posted by VALIENTE
Grado SR60 maybe.
This is just a guess.
Anyway, if you're looking under $100 your best best is some vintage speakers and a gainclone or T-Amp in a nearfield setup. For example, a set of vintage Realistic Minimus 7W can be had for under $50, and sound very similar to older NHT designs.
If you must have headphones, I heavily suggest the Audio-Technica ATH-AD700 for under $100.