[sgrassbaugh]

You can't get all that stuff for $500 to start with. A chip alone will cost you $500. As far as plug and play - with APR you can get direct port programming. You find a dealer, and they plug into your car and install the software on the spot. Zero downtime. Or you can mail in your ECU - and it takes 3 days.
WIth $500 to spend - I would get an intake (I recommend Injen) a new DV (FOrge 007) and a 2.5" downpipe (APR or GHL).
Good luck