The G-Chip and most of those cheap ones just truck your engine into running lean, so they do add a few more hp, before your engine blows up... Keep an eye on the Classifieds here and the other forums. You can buy the classic Edge for $200-$250 all day, I think Jarrett might still have his CTS for sale too
That's about what they sell new for... I'd check around here and f150online/forum and see what they got sitting The PHP forum is a good place to find used ones too
i got my CS used for $350 (100 of retail) just make sure if you buy one used that the previous owner set the programmer back to lvl 0 which is stock or else it won't be compatible with any other vehicle. get them to send you a pic of it set to lvl 0 just to make sure.