If younger going to be there 5 days or less, I don't suggest going off property as most excursions will take you away from the resort all day. I would instead do the included excursions like cat cruise, snorkeling, diving, glass bottom boat ride, etc...
But if you are set on going off resort, the options include a couple different falls, ATV ride, horseback ride, Pelican Bar, swimming with the dolphins. The prices are all over the board, but estimate about $100 per person per activity unless you couple a few things together like a Falls trip with an Appleton Rum tour.
There is a list at the resort of all of the different tours that are available, and you can book them there.
The cost for souvenirs are all over the board. What are you wanting to get? Coffee is about $18 per pound, t-shirts can be got 8 for$20, jewelry is any price you want to pay, coffee cups, wood carvings, shot glasses. You name it you can get it either on the beach or on the included shopping trip.
Food is also all over the board and just depends on what you get. Anything from a few dollars to $20 per plate beers are usually a couple of bucks. What are you looking to buy and where? Are you looking at going off resort for dinner or just grab a bite to eat along the beach. There are lots of options.
Juliann & Jeff
Jamaica Soon Come