We love the Sofitel and have stayed here many times and prefer it to the Hilton, when I priced it for our trip next week it was coming up at 186 pound with the meet and greet parking.
What site did you see it for 240? I just had a look on holiday extras and for beginning of December and it's 190 with meet and greet.
We now fly into LHR, bus over to overnight at the Sofitel, then fly out of LGW the next day.
but £140 is floating around my head at the moment!
This includes a room for 3 (2 ad. 1 ch.) and full breakfast, but no parking. 
I only quickly looked at their own website to get a rough idea of price. What is meet and greet?
If we were to stay then our car will be left for 17 days...do you know how much the additional charges for parking the 2 extra days?
Meet and greet is a great service that we would probably never self park again!
The car parking people meet you at the airport and they take your car, then on arrival back at the airport they meet you with you car, nothing worst than getting on that bus back to the car park!
The price on holiday extras is for 15 nights, I can't entirely remember the price of extra nights but it may be around 5, but you'd have to check that. Last year it worked out cheaper to book the meet and greet parking and hotel separate as we were away for 22 nights.
I will look into the extra parking charges as it does sound a much more stress free way of parking. 
The service in the lobby bar can be infuriatingly slow and the prices of both drinks and food are on the high side. We think the standard of food is pretty good, though.
The worst thing is, it was even more expensive than the Sofitel!
Wish I'd known about the Sofitel back in 2006!
