Lik-sang sells them, but almost all chipped boxes cost over 320USD. The chip itself is only (
X-ecutor ) 50USD, so you pay almost $100 to have someone put it in for you. The X-ecutor made it very simple for people to install it themselves. You should take a look at the diagrams. Only 9 EZ wires. But if you think you might mess it up, I guess premodded xboxes are all you can get.