standard 30-50k miles around 10-12k
standard 50-80k miles 8-10k
standard 80k miles + 6-8k

modded ones not much more tbh.most get put back to standard to sell and mods sold on.ill be putting mine back to standard before i sell as theres a good few k in mods with the kw's,pd,ap's.superleggera's etc
there not really selling just now and the arse is falling out them because people are dropping prices to sell,on the plus side its a good time to buy as your getting a lot of car for not a lot of money