Send 5 different surveyors, and you will get 5 different figures.... What
is a market value anyway? Only what someone is prepared to pay. We can
all look up the land registry for similar properties in the vicinity,
which is exactly what this people do.

Sure at the end of the day its worth what some is prepared to pay for it, it
may be the perfect house/location so you go the extra inch. At the end of
the day though won't the mortgage company only lend what they think its
worth though ?