Whats wrong with it? The manual 700's are rarer and generally more
desirable.

It's what makes the car so much fun :)

To be specific, it's an exhaust driven supercharger that forces air into the
engine allowing it to produce much more power for it's size. No you can't
realistically remove it, turbocharged engines have a much lower static
compression ratio and different mapping in the injection and ignition
computers so if it runs at all without the turbo it won't run very well at
all. Frankly after driving turbocharged Volvos for a while I'm not sure how
anyone could go back, the added power makes a *big* difference. Keep up with
the oil changes, the turbos fail occasionally but usually after quite a few
miles are on them, new cartridge is only about $500 and you're on your way
again for another 160k miles.

A turbo is a pair of fans linked by a shaft, in the simplest terms.  The
first fan is in the exhaust of the car, and the pressure of the exhaust
spins that wheel quite fast--well into the 10,000's of RPM's.

This fan, or turbine is attached to another turbine that DRIVES (rather then
being driven) the uncompensated air into the intake manifold, under
pressure.  The usual intake valves then can allow the air to be drawn into
the combustion chamber as usual in any internal combustion engine.

Since the turbine pressurizes the air there is a lot more air going into the
combustion chamber (cylinder) then a non turbo engine.

Since there is more air going in it's a simple thing to send more fuel (same
for petrol or diesel engines) and gee more fuel--bigger band--more pressure
onto the pistons, more power to the crank...yada yada yada... more zoom!

This 'free' boast has several costs--a lot more fuel used when boast occurs,
and much more stress on the engine.  In addition the turbo is a very precise
machine that lives in quite a hostile environment.

The fuel used is up to the drivers right foot (left in GB I guess), the
engineers at Volvo have, as we would expect from Volvo, taken many different
measures to compensate for the added stress on the engine from a turbo.

Your malfunctioning turbo could well be due to the age, condition, and
maintance of the estate, as well as the driving habits of the previous
owner(s)

It might even be some different problem too!

It would be a very good idea to have a qualified shop, preferably one that's
familiar with Volvos to check out the current condition of the vehicle and
give you your options before you buy the estate.

Removal of the turbo is not one of the options IMHO.

Surely you mean a Shooting Brake, old boy? They drive on the pavement
over there, too.

Turbochargers increase the pressure of the air going into the engine.
Put simply, the more air that goes in, the more power you get out. The
clever feature of a turbocharger is that it uses the pressure of the
exhaust gases, as they exit the engine, to drive the air pump. This is
in the form of a turbine, which supercharges the engine, hence
turbocharger (a 'charge' being the mixture of air and fuel in a
cylinder).

Unfortunately, a turbo is an integral part of both the induction and
exhaust systems, and can't simply be taken off. The engine is probably
also a little different to a normaly aspirated one, with lower
compression.