For Souvenirs it really depends. I buy a shot class at every park I visit and sometimes a shirt. But at Disney that rule goes out the door and the last couple of times we've spent $250-$500.
In Disneyland, there are a bunch of sit down restaurants outside of the resort, such as Po Folks. I think Tuesdays kids under a certain age eat free, and that restaurant is similar to a Cracker Barrel. I learned early on that if you spend some time doing research, you really can save a lot of money and still come away with a good time and nice souvenirs to take home with you. It's helpful that some of the parks let you bring a backpack/bag with you and we always fill ours with water and snacks to munch on throughout the day.
Souveniers are pretty rare, and usually consist of a t-shirt if there's one that strikes my fancy. Even in Disney and Universal, we usually don't buy souveniers aside from toys to quell my Star Wars fanatacism in MGM or Once Upon A Toy.
However, went to Disney World last year, and got free Disney Dining so didn't spend a thing there. But blew it on souvenirs.
As for souvenirs, we usually get shirts each year. We have bought hats and visors in the past, but they usually last more than a year (unless you're wearing them on the fantail of the Disney Wonder while underway. Somewhere there's a dolphin wearing one of my hats.)
Universal is another story. We love Mythos and of course you have Emerils' restaurants (we like Tchop chop much better than his signature restaurant in City Walk) and Latin Quarter is not bad, but other than Tchop Chop we really would not visit USF with any excitement for the food.
SeaWorld is just plain bad! I would brown bag it before eating there. The only decent place for my $ is Sharks and it is overpriced for food. The experience is nice, but you can get that at the Coral Reef in Epcot.
In terms of food, I eat inside of Disney Parks 95% of the time. My favorite places to eat inside the park are Red Rockett's Pizza Port, where the pasta will feed two along with a bread "stick"(more like a loaf) with really good food. My other favorite is the Taste Pilots Grill in DCA, which is "slightly" over priced, but has really good burgers and criss-cut fries!
If I eat outside, I eat in DD at Wetzeles Pretzels (sp?) Cheap, fairly decent food. You can always walk onto Harbor Boulevard and find all types of food too
When I go to my local SF park or any SF park I spend very little money. The food is usually awful so we araely eat any meals at all in the parks and the souvenirs also suck so I rarely buy anything in the park, unless it is one I wont go to for awhile, then I will try to find a shirt to buy.
Now when we go to parks in FLA/CA or other parks on vacation like BGW/Dollywood etc, we will eat many meals in the park and buy alot of trinkets/shirts etc because I find them to be good qaulity and something I would want.
SF needs to lower the prices of the food they serve and increase quality if they want any of my families money. And the same goes for shirts etc that are sold in the park. When one has a medicore experience in a park(which for me anyway is common in a SF park) it doesnt put me in a mood to spend any money at that park.
FOOD GROSS REVENUES
Magic Kingdom (2006 Attendance 16.64 Million Guests)
The 6% who spend 0-$10 generates - $4,995,000The 21% who spend $11-$20 generates - $52,447,500The 21% who spend $21-30 generates - $87,412,500The 16% who spend $31-$40 genrates - $93,240,000The 11% who spend $41-$50 generates - $82,417,000The 8% who spend $51-$60 generates - $73,260,000The 3% who spend $61-$70 generates - $32,467,500The 1% that spend $71-$80 generates - $12,487,500The 6% that spend more than $100 generates - $99,900,000
$538 million in gross revenue.
That's estimated annual gross revenues from just one Walt Disney World park