I didn't buy it on sale just to pass all those saving right on to you as a friendly gesture. My time and effort is worth something.
I never said you should pass on those savings. Just telling you your time and effort isn't worth $20 at this point.
This thread's really degrading with nonsense like this lately.
Imho the only way to really do it is post a wishlist to go with your trade items. This way maybe someone got a deal on a game you want and he or she wants a game you got on a deal. Asking for Paypal or the value in GOG games is just silly. Nobody in their right mind would pay full value (or close to it) when yesterday the same game was 75% off and it's guaranteed to be on sale at least a couple more times this year.
Spring Sales, Summer Sales, Autumn Sales, Winter Sales, Black Friday Sales, Weekend Deals, Daily Deals, Deal of the Week etc. If a game has been on sale at least once, don't even think in terms of full value for it anymore.