Hi Ashy,
500 is a great price. Also please know that you will have the airline charges for bringing your Grey to the local airport, Cage - around 400, Toys, Perches etc. add another 200 and of coarse food for him like seed mix, pellets, veggies, fruits $100 and of course you should get a wellness check-up at the vet soon after getting him to ensure all is well with him ~200..depending on tests they may want to run.
The purchase price of any Bird is just the basic, you can almost triple that once you have gotten all the above initially. :-)