Very good advice here and I'm another vote for on-site. You can stay at a hotel anytime, but staying at a Disney resort is "Magical."
We actually pay for our Disney reservation (room-only) over 11 months and mail in payments to WDW Travel so our room reservation is fully paid for by our arrival
We also purchase (again over an 11-month period) Disney gift cards at our local Giant Eagle grocery store and get the fuel points which we use throughout the year. When we are ready to leave for WDW, we normally have enough Disney gift cards to pay for our food, souvenirs, etc.
We also purchase gift cards to restaurants we know we will be stopping at on the road, i.e. Cracker Barrel, Red Lobster, Olive Garden, BW3s. Another opportunity to save money is to do group meal items like pizza, BW3s, Chinese, and don't forget about the decent priced McDonalds on property.
Another Tip:
Stop at a Walmart Supercenter in Orlando and stock up on bottled breakfast juices, Pepsi, water and iced tea, along with everyone's favorite snacks to keep in the room. In the morning when it's time for breakfast, we take our juices in a tote bag to the Food Court. My bottle of SimplyOrange Juice cost me $1.25 at Walmart but was being sold at Disney for nearly $4 in the Food Court. Last year we saved at least $75 on beverages. Purchasing the refillable cups from Disney is not for us since we don't drink Coke.
We drive from Ohio every year and are Starwood, Hilton and AAA members. We purchase theme park tickets through AAA at discounted price and we're able to spread out that purchase as well, i.e. buy a pass every few months.
Best Wishes on saving money so you can go every year. This year will mark our 29th year at going on a budget. We're pros now.