EddieEC wroteNexus S can be bought under a contract in the US for subsidized price (~$200-300) then the guy pays an amount of money to unlock it and release it from the contract. I think.
you are right, bringing the price back to 530$ then you have the taxes making it 580$, this is how I got it.
but selling it at 460$ seems very illogical unless there is another version of the phone which is very unlikely.