Hey man if you are looking to do a retro-fit it will in NO way cost you 500 dollars. Mine cost 115 for projectors, HID's, and odds and ends to do it. Here is a shot of my cut-off and light throw and such. We are waiting on a new pair of HID's but you get the idea. Also do head to HID planet as they are good too.
^^Granted this was the test fit and with ONE projector and HID.
By the way i had ebay lights too. Sold them and took the extra cash and pocketed it because i already had this stuff spare. These wer actually done in stock housings.