There are some amazing hotels within walking distance.
HOTEL: Adagio - cheap and cheerful, 20 minutes walk to Disney and a bus too if you don't want to walk
HOTEL: Hi-Park - lovely, bit more expensive, but MUCH cheaper than Disney hotels and 15 minutes walk to Disney (plus bus services too).
Bonus of above hotels, is they have their own cooking facilities. This will save you a fortune, as food in Disney is expensive. These hotels are in a beautiful shopping district called Val d Europe and there is a massive hypermarket in this centre, to get all your food. Amazing.
TRAVEL - Eurostar is so easy. If you can afford to go direct to Disney, this is even easier. If not, go to Paris, get off a Gar du Nord, get tickets to go to Marne Le Vallee (disney) and go to Les Halles train station to get the RER train to disney.
The only other expense will be your Disney tickets. You'll be better off getting a package deal on a few says, not pay per day. Alternatively, get annual passes. Then you can go all week.
PM me if you want any tips. I love doing expensive holidays on the cheap! x