Nintendo 3DS for cheap?

Nintendo 3DS for cheap?

Does anyone know where I will be able to find a Nintendo 3DS system cheaper than what Gamestop sells theirs for because I can’t afford to pay $170. I will even take a used one as long as it is in good condition ( minimum amount of scratches especially to the screen and virtually no cosmetic damage).
I am seriously considering selling my PSP 3000 4GB memory stick and the games that I have with it just so that I can come up with some of the money. YES!!! I want a Nintendo 3DS that badly. Oh and speaking on the note of PSP, please DO NOT suggest that I go and get a PS Vita because I don’t want one of those right now. Only answer my question if you actually have an answer regarding Nintendo 3DS.