does anyone know if the tunnel prices get lower if you leave booking until the last minute....or is it like easyjet where the prices go up nearer the date???

No, it's all according to time of day. I.e. it's cheapest during the night and very early morning.
Edited to say: I mean what time you TRAVEL, not what time you book. :)

hi yes i realised that but what i was meaning was for example....if i book a 9am slot on october 1st today....would it be same price if i book the same slot/day but book it  only a couple of days before departing on october 1st?? ie do the prices come down nearer the travel date?

I don't think so - I think the price is the price, whenever.

I was under the same impression as JG but just checked and found this:
http://www.eurotunnel.com/ukcP3Main/ukcPassengers/ukcProductsServices/ukcTicketsAndFares/
It says you can save money by booking earlier -but then I can't find any further info on it..

From my experience the earlier you book the better. I have tried to leave it to the last minute before, when not imperative we go, and the price went up quite steeply.
Jeff.

My friend went on travelzoo and as a special he and his wife went return on Eurostar at £10 return yep £10 to Paris. But it has to be at a time that is not during school holidays ect. Problem is unless you have flexible time off you cannot really take advantage of cheap last minutue prices.
I also noted last week you could get a virgin return train trip from London to Glasgow for £1 on travelzoo. So they do sell off spaces when they cant get bums on seats. Give it a look.