You have a few options.
Our first trip, we stayed offsite. We learned very quickly that staying "onsite" was just as much of a hike to get to the parks (unless, you're at a monorail resort and wanting to go to the Magic Kingdom, for example). But, since WDW is a massive city, even "onsite" is really far from the parks and dealing with Disney transportation and busses would be a hassle for our family.
So, we liked staying offsite and did it again last trip.
We rented a home from VRBO that we loved - four bedrooms, three baths, our own pool and hot tub, full kitchen - and it was like $90 a night! We also liked the Ramada Inn, which was SUPER cheap - we found deals through the Disboards and mousesavers.
Secondly, we rented a car from
www.mousesavers.com tips - we paid like $220 a week for a minivan. You could go cheaper than that.
If you must fly, try southwest
www.southwest.com - they have great air specials right now - from our city it is $59 each way.
We bought our four day park hoppers (back then this is what they sold) on a tickets website - ticketmania, probably.
Other ways to cut back, if you want to go with a package - travel in a certain season, stay in a value resort, cut your trip down by one day, etc.
BUT - I really found booking a room only even onsite and adding tickets, etc was way cheaper - sure, you have to pay out of pocket for meals - but it works out for our family because we'll do one or two "big" meals during the trip (usually a character breakfast and a nice dinner) and then eat counter service. There is so much walking you're hardly ever hungry, and when you are you don't want to stop for two hours just to sit down and eat
And the food is SOO good - everywhere - that you don't feel deprived.