pratorious"Consider Grado SR 80e"
You must be kidding,on no planet in this galaxy could ANY Grado can be considered warm!
You want warmish & $100.00 you want Sennheiser...Sennheiser HD 559 Open Back Headphone
"Overall the sound quality is very good. Not in the class of the more expensive models from Sennheiser, but then you wouldn’t expect it to be. If you like a good all-round sound, with a rich, dynamic bottom end, then this could be the best Headphones Under $100 for you."
Pratorious must have been unaware that the Grados are specifically not warm. Perhaps the RS2E is closer to warm, being almost neutral. I've the the RS125e, they are pretty close to the SR80e, and they are bright, forward and pretty detailed, certainly not warm.
I second the Sennheiser suggestion, their house sound is on the warm side. I'd also suggest going to Youtube, and search "best headphones under $100". There will be some warmer sounding suggestions.