Perhaps I am misunderstanding what you typed, but I do not need to ship my gc anywhere - I can just supply the claim code to the prospective buyer. I think $40 is fair, 80% of value.
You could probably sell it for $55 on eBay and net more than you are asking 
... Anyway, I'll offer you $30 and I'll even pay first without escrow. You can take the $30 to buy cases of tissues and keep on rubbin' it out! I'm a gamblin' man.