Whats it worth?

Sorry dont know if this is the place to post this but what would you guys pay for an unregistered AU S1 I6 Auto. It is fully ready to go over the pits and the guy has paid 2k so far getting it ready. It has 300k on the dash but the motor and gearbox is tight and clean. Has a TS50 bodykit and 2 1/2 inch exhaust. Also has superlows.Also has brand new pioneer sound system($500). Just curious he has given me a price but i want to know what you guys think its worth. Cheers.