Valuing a 2nd hand bike

[Steve vRS]

I have been offered a TT bike second hand. I don't have all the details yet but in general, how do you value a bike? For a car, it's easy - look at Glasses guide or have a trawl through the Trader. But where do you start with a bike?

This could be academic however, as my wife may well remind me that we are saving up for a new kitchen.

Steve