I saw this today on Midnightbox.com.
Repraper ABS 3D Printer Filament Bundle (Diameter: 1.75mm, Length 400m) - Choose From 5 Colors
http://www.midnightbox.com/cgi-bin/item/10064262-110/repraper-abs-3d-printer-filament-bundle-diameter-1-75mm-length-400m--choose-from-5-colors-.html

They offer it for $35.95 and say the retail price is $119.99.
I just don't think that's right. But I am new at getting into the 3D printing world, and really don't have a base of what's a good price on filament.