If staying off site, and not renting a car, you'd need to factor in transportation TO your hotel as well. I usually use a towncar when staying on site, and either that or a cab is over $100 round trip, plus tip. Sometimes you can get a good rate on a car rental, but you need to check now and keep checking (our week before Christmas is way up now, but I got a killer deal many weeks ago).
I'd say weigh all your options. If you can get free dining at a value resort, you may be better off than off site, paying for meals, paying to get to and from the airport, and the whole convenience factor.
Do you already have tickets? That is one of the biggest expenses, but if you don't have them already, then the free dining is also good since you have to buy at least one ticket for each person.
I'd take a good look at your budget and go from there - you may be surprised.