If you don't fix it you probably should part it out. I don't think you will get that much for it without it running, and who knows if there is head damage. This is just a guess, but you could get 3500-4000 for your car running. There is a 95 GSX on fleabay now with 130k for a buy it now of 3895, but it does not have any mods listed, but it is a GSX. I got my 97 GST in April in pretty good condition with 65k miles on it for 4500.

 

i say get it fixed. for the money your gonna spend to fix it you will by far make up when you go to sell it. So its definetly worth fixing. Then as for the worth. I would say around 5k i guess with the mods you have.