In terms of choosing valuable things to spend your money on, this one is definitely recommended by me. Sure, I might be biased, but really, it's about more than getting people to simply sign up for my retreat. Frugality is all about a lifestyle choice and an overall balance in your life. There are times where “investing” in something that will give you far greater reward over time is worth it!
It's like hiring someone to do your taxes rather than doing them yourself. Sure, it costs money. But if you can save more in the long run by having someone do it for you correctly the first time, it ends up saving your family money in the end. See how that works?
Anyway, come have fun, and I promise…it'll be worth it!