If you're talking about the 100ml limit that is still in place (heard a rumour it'll be ending sometime this year) then officially it's the limit of that in the bags - I believe the guidelines are containers no greater than 100ml and no more than fits flat into the plastic bag which is about 2/3 of the size of a piece of A4 paper.
Not sure how they got cartons of juice through - I do know you can buy these at
Dalaman if you sell your soul! I get a few of the travel size bottles you can pick up at pound shops and fill them with vodka works a treat on the way out to save on flight priced drinks (added to a bottle of diet coke nobody can tell!) but doesn't solve the overpriced Dalaman situation. You could always book in their lounge, they don't do alcholic drinks in there but you could easily be "in profit" from just a couple of soft drinks with their prices! Book it before you go for the cheapest price, and if you have a quidco account (
http://www.quidco.com/user/465328/) they give you cashback too so it's overall even cheaper!