Other historical tours?
If you have a car, and don't mind getting up early, the battle of Lexington is re-enacted every year on Patriot's Day (aka Marathon Day). Unfortuately, its at 5 am, though.
It is budget, however- Free!
Other historical tours?
Oh shoot! I'm glad I foudn out before our next trip, though! Shoot, walk over there and see it closed- I'd have a couple of ugly kiddos!!
My sister and I used to love visiting the Christian Science center next to the Prudential Center (and right next to where you are staying as well). We are not Christian Scientists, but the tour of the church is free and we just thought it was the most amazing place. They have a good information center and an awesome walk through globe. It has a walkway that goes through it and you can stand in the center and all the countries are illuminated around you. Again- free and very cool.
This is called The Mapparium and I agree that it is a great place to visit.
http://www.marybakereddylibrary.org/exhibits/mapparium.jhtml
As said, there is the aquarium, Museum of Science and Children's Museum. Nothing budget about any of those, lol (though if you have a passport membership from another science or children's museum, you can get into MoS or CM free.) Out of the 3, our choice would be MoS for your ages.
Bolding above is mine- we're members of a museum here, and getting into MOS and children's museum FREE! If your kids like museums, I'd look into a local museum and see if they have a reciprocal deal with Boston museums..
Our kids are almost the same ages and our trip is the week before yours!
We're doing a side trip to Plymouth, our kids are REALLY into history. Skipping Salem-not into witches. Also a freebie- the musuem of fine arts is free Wednesday nights.
We're eating at Fire and Ice (Berkeley and St James), maybe McCormick and Schmidts (Faneuil), maybe South Street Diner (Kneeland St), somewhere in the North End. I'll bump up my thread for you- there's a couple more ideas in there.
Kidquest We're There, Boston
There are scavenger hunts at the various sights, bus tour bingo, count the flags at the state house, things like that that make historical touring fun for kids. These books are perfect for the 7-10 year old set, and you have a great memento of the trip when they're all filled in. Amazon sells them.
Have fun!