I've held parties there many times. There are a few time slots to choose from, 1.5 hours. (time slots also depending on which Mac)
Fee is each child needs to pay $12 for some gifts (but not good at all, you need to buy some in addition) + food consumed. Decoration charge is not complusory.
I think th charge is about $30+ x no. of ppl (adults or kids) if the kids are not babies. (& assuming no decoration charge)
service also depends... don't choose those which are too busy...