Good luck with your current project.
I try my best to make calculated/informed decisions, and to pay almost half the labor cost ($165) upfront (in the form of additional cost for the parts) as a 12 month insurance policy on the labor didn't seem like a smart bet.
I assume there is much less then a 50/50 failure rate, which would put me ahead of the game, but as my statitics profecssor used to say, "you're not doing hundreds of samples... in this one instance the result will either be '0' (failure) or '1' (no failure)".
As i know a little, but am far from being a mechanic, i just wanted to confirm that i was making a smart decision and not trying to save money where i should be willing to spend a bit more.