My advice is to only buy over the normal price if it is absolutely free of any major faults. For example I bought a 320 coupe over the odds and then found the rear screen demister didn't work the a/c didn't work there was a slight head gasket leak and later after driving it the alternator blew and cooked the battery.I could easily spend £3k putting it all right but with rising fuel costs and other taxes it probably isn't worth it. Rarity can have its own price tag.