It is one of the best investments you'll ever make. Not only from the aspect of what you learn, but for the people you meet. Price-wise I dare you to try to find a better deal, anywhere. I've been three times and just wish that time permitted me to continue to go. Do it!
Remember those who put their lives in danger for your sake.
I enjoyed it a great deal and learned a lot the first time; not so much the second time. When I did it I didn't think the practical at Level I had much to do with actual coaching; also the written test was pretty useless--badly written and having little to do with actual coaching.
"Arm yourself, Watson, there is an evil hand afoot ahead." -- Dennis Pierce, 2010 Bulwer-Lytton contest, detective fiction category runner-up.