I don't want to sound like a party pooper, but I have always stayed away from souveniers as much as possible, so DD11 & DS8 don't expect much. I find that they end up in the garbage quickly. I limit them each to $10-$20 per TRIP!
We did pin trading last trip to WDW, but I brought pins with that I had bought on clearance. They actually loved this activity. DS8 (5 at the time) loved it more than any ride.
We just got back from a DC trip, and they got to spend $5 out of my pocket each. They each spent $10 of their own money.