We went for 9 nights in October. We had $500 Disney Dollars plus some cash for odds and ends. We were on the dining plan, and I had a credit card for stuff we charged back to the room. For some reason last night I decided to add up all we spent OOP. Bad decision!
We spent over
$1000 for miscellaneous stuff!

SHH! Don't tell DH!! We already had the tip envelopes for Mousekeeping and Magical Express filled before we left home, and I had an envelope with money for locker rental each day. So the huge amount of money we spent was mostly nickel & dime stuff that added up to a whopping total! To be fair, $150 of it was our share of an IllumiNations cruise, another $150 was dinner at Fulton's, and we spent over $250 on souvenirs. We also paid OOP for 2 additional TS meals, so that was another $120. The other $365 I can't quite figure out.

It is some combination of extra tips, cab fare between resorts, airport stuff (dinner before departure, candy, magazines), OOP snacks & drinks at the parks, cash that DH and DS spent in the arcade, etc. I can account for all but about $90 with receipts. I am relatively sure I didn't just LOSE $90 somewhere - I think we spent it. Easy to lose track of $10 per day.
DS had his own money, I think $110, which was completely separate from everything else. He spent all of that, but that was why he had his own money. He did well making it last until the end of the trip.
I absolutely think we would have spent less if we would have had less on hand TO spend. Instead of using the Disney Dollars to pay off the room charges I just bought more stuff and left the room charges on my credit card. Naughty, naughty.