The 4/3 is a great deal. depending on the age of you child and how much each of you eat, the quick service meal plan can be a big help to you as well. Last year we did a fridge swap and it worked out well. we were there for 8 days, and the swap only cost us $25US. -- would have been 80+ to rent from the resort.
if you have CAA and can go during value season, you can really save money too (Pop century reg. room cost us $55+tx per night in Jan/08)
if you are flying and only plan on doing disney, take advantage of Magic express...its free! We had a very good experience with this service.
if you are close to the US take advantage of the low fares for flying out of a US city. we flew out of detroit on spirit for $55+tx each way. just sign up for the email alerts and know what dates you want. We have flown spirit each time we have gone to Disney and it has been smooth sailing (and flying

)
You can save by using a ticket broker too. we used undercovertourist.com last year and they were quick delivery and good to go when we arrived. (you get an extra discount if you sign up for mousesavers.com newsletter and use their link to
undercover tourist site)
I didn't take the tickets out of their sealed package and when we arrived, we just went to the concierge desk and they put the park tickets right on our room card (key to the magic or whatever its called i forget) NO Problems at all. this way we only had to carry arround the one card.
We live in a border city so after crossing into the states we stopped and bought some cereal and snacks at wal mart....I think you can do this in Canada and cross with most things but it was just as easy for us to stop on the way to the airport. we just packed the stuff in our suitcases for flying. we bought milk at the resort (can get 1/2 gallon jugs right there) which is why we did the fridge swap. it was great with the kids!
our final total after room,flight,food,souveniers, parkhopper tickets for 6 days, and sleep/park/fly came to just under $3000.00 CND (remeber last yr this time money was at par)
There are all kinds of things to save on and I learned most right here on the Dis. it's a wealth of info!
