edit, still a little bit confused as to how this thread works and don't want to post any offers until I'm 100% sure how it works
You just post what you are interested in getting and what you have up for offer. If someone wants to trade with you, they will contact you through PM. As you are new to this forum, expect to have to go first in any trade, as people are worried about scammers.
Also, you are not limited to GOG games.
A simple rule of thumb is "lowest rep goes first", though there can obviously be exceptions.
Okay, thank you for the info. I would have no problem with going first.