In my view, these prices are probably realistic. At Technoclassica Essen we've seen cars in condition 1 go for in excess of €100,000 regularly. These prices reflect probably what most cars go for in adverts from private sellers and through dealers.
Do not that the € / $ rate has absolutely no impact on the European prices... it just makes good cars from the US seem astonishingly cheap for us Europeans at the moment, the same way it makes our cars look ridiculously expensive.
The risk associated with buying a car through ebay, or remotely in any other fashion, is such that there is very little effect that the trickle of overseas transactions can have on price in either market.
Now if we set up a little overseas trading company with trusted sl113 members buying cars in the US for trusted sl113 members in Europe to sell, that might be a different matter...
Peter
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http://bali.esweb.nl for photographs of classic car events and my 1970 280SL