[H] Sins of a Solar Empire Rebellion, Space Hulk, Spore, TellTale Collection [W] Tf2 & Dota 2 keys

If no one else responds, I'll take spore off your hands for 2 keys (costing me 50% of the game price).
Also Space Hulk for 3 keys (costing me, again, 50% of the game price).

Maybe I'm mistaken, but I was under the impression that keys are worth $2.49

Assuming that's correct, isn't your offer for spore and space hulk exactly the going price on steam?
6x2.5 = $15 for hulk
4x2.5 = $10 for spore

Is there a cheaper way to get keys?