Selling Gameboy Stuff?

To answer you additional question first, you should sell each system individually. If you sell them all together, you won't get as much for them as if you did selling them separately. My advice is to sell them on either eBay or Amazon to get more money. Trading them into EB Games or Gamestop will just be a waste of time and effort since you will get about 1/4 of the money you would get selling them online. Another thing I advise is for you to sell Pokemon Blue, Red and Gold separately because those old Pokemon games still get high bids on eBay (provided they have their original manuals and the boxes). Sell the Gameboy Colour with all other games because the others are very much worthless. Then sell the Gameboy Advance with all of the games and accessories (cases and adaptors) and when selling Pokemon Gold, sell the guide with it.