I am glad you are satisfied.
I will say that unless you got something valued at greater than $300 (as the cage that you were getting such a great deal on) then you are not getting something of greater value than you paid for. More than you paid, sure, but not more than what you were to receive.
It is safe to say you would not have paid over $300 for the cage, or you could have bought it from rept-racks. You were getting it for $120, so you jumped at the opportunity.
It is as if he said "Hey man, I will give you 3 $100 bills when I get them if you let me borrow $120 now." You gladly accept the deal, and when he doesn't get the $300 that is rightfully yours, he changes the terms and offers you $170. You are money ahead, but would you let a stranger borrow $120 for a few months without being given reassurance that you would be getting the $300?
You are lucky to have gotten back more than you paid, but he still scammed you.