Yeah, we need a little more Info. Is this $800 including transportation, like airfare or gas to get here, assuming you are driving? Food? Tickets?
Hotels: Around MCO you could probably find a whole bunch of decent hotels $100 or less. I assume that most of them will provide a shuttle to WDW, but the frequency may be less. You also may have to pay a fee, say like $10-$15.00 for a roundtrip ticket to and from, so take that into consideration.
Tickets: at $109.00 ( unless surge pricing is in effect) you are looking at spending $763 for a week, with no park hopping at the moment.
Food: Like the other person said, look to spend at the minimum $25.00 per day on food. Now if you Hotel provides a complimentary Breakfast, that's a plus..
Anyway, bare minimum, for a week, $800 is not gonna cut it if that is supposed to cover your whole trip