I have a GT Xizang titanium 18" mtb from 1998, excellent condition with original Rockshox SID forks (need a service but have magazine from 1998 with full servicecguide). full XTR group set, trick bars, stem and seat. Mavic rims all in great original/retro condition. I am planning on selling it, possibly on eBay can anyone give me advice as to the value? I have had it 10 years I have the original receipts it cost over £2000 to build in 1998.