I've bought the fastpasses in Universal the last couple of times we went. It does sort of take your breath away when he calls out the total for six of you, but I've found it worth it.

They're supposed to mark the ticket at each ride so you can't use them twice, but we found that if the main line wasn't too long, the staff didn't bother to mark them, so we could go back again later for another go.

Exactly the sort of unscrupulous behaviour, I suspect, which gets the people in the main line all upset. Sorry.