$1,000, it's a 23 year old car with 160k miles, exhaust and "cold air intake" are moot points in the price. You can buy a nicer 97+ 3800 powered Grand Prix, if that is what you have your heart set on, for 2k.
http://www.ebay.com/itm/Pontiac-Gran...m=122026071524
Follow this guide to fix the issue with this car and you have a much better car. http://www3.sympatico.ca/aepa/blowerinstall.html