Even if unused, it would still be a 20+ year old vehicle, with degradation of electrics, rubbers, etc, etc... Personally I'd struggle to justify paying much more than £20-25k for a stock 80 series, regardless of the mileage etc.
One that's rebuilt, decent usable mods, etc.. maybe a bit more. But north of £30k? Dunno...
One that's rebuilt, decent usable mods, etc.. maybe a bit more. But north of £30k? Dunno...