Depends which model , there will be more of a difference with 911's and less
with 944/968's but that is mainly down to the age of the RHD versions of the
cars. Check www.autotrader.co.uk for prices. The older the car the less
difference , or so it seems.
a second hand LHD is cheaper to start with due to the less desireable nature
of LHD in the UK and so the re-sale will most probably also be so.
If its an everyday driver some insurance companies either won't touch it or
want a premium for cover , if you go low mileage (5-6K a year ) you can get
classic insurance , no no-claims is needed and for an example my 944 S2
costs £320 a year.
Paul