Value of a nes challenge set??

[ATARI7800]

Does anyone know how much a cib one should sell for I'm thinking about selling mine 

[NintendoKing]

Roughly $60-80 as NES collectivity has gone down drastically over the last 2 years, also the internet has made boxed NES much easier to find thus lowering their worth.

[manuel]

Let me know if you decide to sell it. I might be interested if the price is right.