Here is a UK run RV web site with links to builders web sites. There is a 'for sale' link that might give you and idea on the market value of a built up RV
http://www.rv6.co.uk/
At our airfield we have a trigear 100HP Europa, and an RV6 both have no problem with our 400m grass strip. Both are used for short pleasure flights and touring. Both owners love them.
The biggest difference seems to be the fuel consumption of 100HP Rotax V 150HP Lycoming.
CC