I've just come across nadaguides.com, which is US based, but claims to give a used boat guide price. Does anybody know how accurate the given prices are for boats in Europe or if there is a European equivalent?
From a position of complete ignorance, I'd suggest that they will be less than helpful as a guide to European prices. Reasons are:
1) A completely different marketplace, with mostly different boats available. Even nominally similar boats will differ in detail.
2) A completely different regulatory framework; RCD and CE (for example) are not required over there, and there have been many threads suggesting that it is neither trivial nor cheap to bring a US boat up to the standards required in Europe.
3) A more "commodity" based market, akin to that of used cars.