wrote:

Hi Ken. There are 2 adults and 3 kids (all science mad). Using
http://www.thetrainline.com the cheapest we can get from where we are
to London is 151.20GBP, and it takes much longer door to door too.
We're down in Dorchester and I've driven it before in about 2:30h
(M27/M3, especially on a Sunday). The train/tube will take about 3:45h
if we're lucky, plus changes and pushchairs/lifts. We all fit in a 1.1
engine car. We don't use the train enough to justify a family
rail-card? The kids really love the train, and I don't particularly
like driving, but for the time/price I didn't think it made sense. PS.
Wouldn't do this on any other day but a Sunday...

FYI, you can do the journey for £101.60 (with One Day Travelcards all
round), *including the cost of a Family Railcard*. I understand this
might still be a bit steep, especially given the extra time involved,
but worth bearing in mind if you find yourself in a similar situation
in future.

--
John Band
john at johnband dot org
www.johnband.org