Catalunya value.

Hi guys, I've been an avid reader of the site for a few years and always been impressed with the knowledge and experiences of the members on here. Its that knowledge and opinion that I'm after if that's Ok? I think it may be time to sell my 1998 Impreza Catalunya. I'll give a quick run down of the spec. Its got a 2.5 bottom end with forged pistons balanced crank, version 5 STI heads, TD05 20g turbo, 5 speed 05 gearbox diff and driveshafts and Apexi ecu running about 350bhp, potential of over 400. The car itself is the very last numberd car which is number 203. She's covered 79000 miles and the body and interior are completly imaculate and original. All the books full history and both keys. I've put a lot of time and money into her over the years and will cause a lot of tears when she does go. Not sure of a value and that's what I'd like help with. Thanks for the help.