"I will not trade all keys for a single copy of GTA".... they're all bundle keys, so worth next to nothing, Terraria goes on sale for less than half of what GTA is worth, you're seriously lowballing and you don't seem to see it.
Yes it's a lowball. Get used to it here. People offering their leftover humble bundles and especially origin bundles for great games that aren't discounted often.
[H]
Terraria
Limbo
Amnesia
Swords and Sorcery
Psychonauts
Bastion
Super Meat Boy
Lone Survivor
Braid
[W]
GTA IV