My two budget-fi set ups:
Ipod Nano 3G ($40) -> KSC75 ($15) in Sportapro Headband ($25)
Ipod Nano 3G ($40) -> MP 9927 ($8)
Two great sounding rigs falling well under $100
Also got a Cmoy kit in the mail from Fred_fred which will add another $30 to both rigs
I also really like the idea of a portable budget rig contest!