I'm thinking it depends on the relationship they forge with your kids and how often your kids use the program. I've got a 2 and a 4 year old, we're going on a 7 day cruise. Since I'm a SAHM, I'm looking forward to them spending some time in the camp, lol. I'm guessing we'll likely end up giving someplace around $100 per kid for the week. The people who care for my kids definitely deserve at least that - in my opinion, that's the most important staff we'll deal with. Heck, they are WHY we chose Carnival over the other lines!
Just my 2 cents.