The cracks look pretty old to me. I don't think they are shipping cracks.
That said, Jason, while I agree you are 'right' to ask to be held harmless in the deal, in the real world I think you should be content to get $2400 back. The cost to return the gun, and definitely the cost of your FFL*, you should absorb and chalk it up to lessons learned. Even if you don't get the $30 for the shipping to you, forget about it. Rest assured you've done more than $100 worth of damage to Game Fair's reputation, even if that's not what you set out to do.
*It's not the seller's fault you don't have an FFL - that is your "cost of doing business".
