How many are in your family..adults & Kids? That makes a difference in my opinion. Also your own personal spending habits will make other estimates off. But, all that said, here is what we budget.
We are a family of 4 (2 adults 2 DS's 4 & 8). The main considerations for extra $$ for us are.
1. Rental Car
2. Refillable Mugs (@ resort $13.00 each)
3. Souvenirs - I budget $10 per day per person some days we spend more,
some less
4. Dole Whips/Fresh Dole Pineapple Juice - These are a MUST HAVE for all
of us. If we are at MK we budget an extra $30.00 for Dole..not
incl.
5. Wal-Mart items. We always make a stop at Wal-mart before we check-in
to the room. We buy beach toys, towels, food (mostly breakfast) post
cards and other extras. Usually around $50.00
6. Photpass photos. We try to wait until we get home, but usually don't, so I
budget $30.00 on photos.
7. Extra snacks. We all tend to eat 2 snacks per day (popcorn & ice cream
since only 1 snack is included, we budget $12 per day extra.
8. Kids Clubs. My kids LOVE the kids clubs (almost more than anything else
at Disney) so we have to MAJOR budget for 2 stays during our 10 day trip.
For 2 clubs, 2 nights 5 hours each is $200.00. Much worth it, but big $$
9. Water parks if you don't have option on pass. We have it on our passes
but they are a MUST DO, if you have it or not..our family of 4 $95.00
Basically, we budge $150.00 per day above and beyond "prepaid" costs (rental car, room, tickets & food) which is not a ton, but enough for us.
Good luck!!