Disneyland Paris have a BOGOF deal on tickets on their French website at the moment, which would be ideal for those planning to visit during the February half term. Every adult pass ( 45 EUR on weekdays, 55 EUR on weekends) entitles you to a free children's pass, which usually cost about the same as an adult ticket. Please note that these are 1 day 1 park passes- 1 day 2 park ones cost 60 EUR each but most people advise against visiting Disney Studios anyway.
So for a family of 4, the passes would work out to around £ 140 or £ 35 each for 2 days as opposed to the normal price of around £ 100 each.
This deal works out a lot cheaper than some of the other 'children stay/play free' deals that Disney regularly run since they require you to stay for 4 or more days and come bundled with their crappy and overpriced resort hotel options, which usually end up bumping the price significantly. This would also suit those planning shorter breaks which are not usually included in offers.
You can find much better value accommodation minutes from the Park, for instance Hipark, which are much nicer and additionally offer you cheaper eating options as well.http://www.hipark-residences.com/web/h/fr/accueil-j_6.html
I haven't worked out a head to head comparison with Disney's own 'offers' but I would expect this deal to represent a significant saving, especially for those planning a visit during the February half term.
-Change language selection on the Disneyland Paris website to 'France' and 'Ill De France'. Use Chrome or similar browser with auto translate as the French website is..ahem..in French
-You should see the deal displayed on the Welcome page, if not, click on ticket offers to find it.
-Price of passes and valid periods are displayed on the offer page
-Enter your UK address in the address box although the country is set to 'France' by default. It should not matter as the tickets are not posted out anymore (FWIW I used the address of the hotel I would be staying in)
-Choose tickets, complete payment and print out the passes
Those looking for accommodation, check out http://www.laterooms.com-plenty
of decent choices there for half term week, for instance, family suite (sleeps 4) at Hipark £220 for 2 nightshttp://www.laterooms.com/en/hotel-reservations/264574_hipark-serris-val-d-europe-serris.aspx