I have made 8 trips to WDW since 2007, and I have done it on a fixed income. I get asked all the time of how do I do it. It's pretty simple do when you know what bills you have each month. I have gotten to the point where my bills are low. I have gotten rid of Credit Cards. Now that I don't have to make those payments I took that money and put it in a Savings Account. After about 6 months I have money to pay the Disney part of my trip.
I have another way to pay for my air fares. I found a site called Swag Bucks. I can make $100 a month. They do have a pay out that you can get cash though Pay Pal. A lot of airlines to take Pay Pal as a payment so that is how I pay for my air.
Since starting this saving plan I can go twice a year. On my last trip I bought a Annual Pass.