We do Disney every yr and have since 1999. We purchased DVC back then and whenever we price out another vacation, Disney always ends up being cheaper. Our home base is BWV, so we do stay luxury and the past 4 or 5 yrs we have always had a Boardwalk view.
I know OP said that they liked the monorail resorts because of the wheelchair, but the Epcot resorts are just as good. We can walk to Epcot and DS. What we like to do is walk through Epcot and take the monorail to MK. So, technically the only resort that we would have to take a bus to is AK and we usually drive there. Just another thought for ya!
We usually vacation the end of June (when the kids get out of school) or the end of August. We have also thrown in a December trip before too. On our end of August trip, we buy APs so when we come down the following yr in June, we don't have to buy passes. June is our cheap trip (accomodations already pd for as is our passes!)
We do purchase the dining plan, basic, but this was our method of eating before the dining plan existed, so now it is actually cheaper for us with the fixed price.
We also have to fly down (dh won't drive from NJ.) We can usually get air tickets for around $600 for our family of 4. We do rent a car and I try my best to get a cheap full-size rental. We like the luxury of driving from the airport and stopping at a store. Also, that we can drive to some parks and DTD if we choose. Our trips are usually 8 or 9 nights, but due to fact that we are travelling with family and the dates are not exactly what we wanted, our upcoming trip is only 7 nights.
I know that their are ways that we could cut out even more if we wanted to, but this is what works for us. We do pay cash for everything and enjoy going home. Dh coaches a soccer team that he gets paid for and that is usually our spending money and our dining plan money. We buy the plane tickets as early as possible and will either use our tax return or my bonus money. We do not allocate money on a monthly basis, but we know when we usually have chunks come in and I then put some of that aside.