Looking at a 911
 

So a guy I know from work is selling his 1993 911. It has 75K miles. He has upgraded almost everything with Porsche parts. New interior, new soft top, new suspension, new clutch assembly, new tires. Not sure what all he's done, I need to get the information from him as to everything he's done but I know he's pretty much rebuilt it. Has 300hp due to all his upgrades. He offered it to me for $24,000. I know he needs it for a quick sale so he can put a down payment on a house. What kind of money is a car of this magnitude worth? do the upgrades increase the value of the car? I drove it yesterday and for my first time driving a porsche I must say that the power alone impressed the hell out of me. I drive a 2003 Audi A4 turbo right now which is a smother ride but not nearly as fast or as stylish.

Any suggestions, recommendations or can anyone point me in the right direction?

Sorry if I posted this in the wrong forum.

Thanks in advance for any help.