Welcome to AP.
IF u dont sell here quickly, list the games on Ebay (as well as here) and see what top prices u can get. Gumtree equals scammers mostly...
Start the Fishtales/Bride of Pinbot at a much higher
Buy it Now amount $ than what u really want, and have a
Make an Offer part on the ebay advertisement. Works the best to get higher amounts n people will offer what they feel is appropriate. Then u can get a short consensus from real buyers.
Gumtree seems to be full of scammers, Ebay offers
some protection, not perfect ofcourse, but try n get cash on pick up, or bank transfer etc. Always ask for peoples mobile and work numbers etc so u can sort out the scammers from the real people.
Hard to give u a real close n realistic value on your games until u place some photos up. Generally Joe public will pay a little more for your machines than regular collectors, but with regular collectors u get serious buyers who are 99.99 percent good people and ethical.
Good luck with your sales and welcome again to AP.