How much does an installation kit amplifier roadworks for retail?

My BF bought a box of material at a RadioShack auction. One theme is a kit amplifier installation projects (model AW-ak35). Now I would like to sell this, but obviously could not find a sales price elsewhere. Does anyone have a ballpark figure? While I'm at it, the price of GameCube Game Switch? Very grateful for any input!

Price Retail Metra AW-AK35 is about $ 62. GameCube Game Switch? Is that the RF switch and modulator? If so, $ 29.95.

Christie’s Star Trek Auction: PART 1