Just got back from doing this last week. It was a lot of fun, but very exhausting...and bruising. I think I found new bruises everyday for the rest of the week! I'm older (33) and not in particularly good shape so I was particularly suffering trying to lug the 9ft board back and paddling back and forth after each wave, but I did get to stand up momentarily by the last attempt. The kids did great--most stood up the first or second time they tried!
Logistically, I think it ran around $125. They only offered it on Tuesday mornings, and you had to be at Typhoon Lagoon by 0545 (ugh.) You didn't need to pay for park entrance, but you couldn't stay in the park once it opened, either...you got marched out in a group, in front of all the millions of people waiting to enter. 2 instructors were in the water, so after some dry land instruction, pupils went out one at a time to each instructor, surfed one wave, paddled back to the other instructor, surfed another, and then paddled out and walked back to the line. Most people got around 6 tries...I don't think I could have lasted for another...