[oldschool]

Should have at least 2GB flash and a screen.
I am not willing to pay more than, say $80.

All my library is in AAC (.m4a) and that's the reason I am looking for a small player that I can easily take with me during jogging.

I was also considering the iPod Shuffle, but the lack of screen is a big drawback.

 

[oldschool]

Seems the Creative Zen Stone Plus supports AAC and has a screen. 2GB for <$40.