I think it is too expensive for what it is. I borrowed it when Natty was a baby and I didn't find it particularly helpful. I think it is worth watching, but I'd borrow it rather than buy it.
Obviously you need to know that it isn't going to work all the time - babies don't always follow the rules But, if it helps parents feel more empowered and gives them more ideas on how to care for their baby, then it is worth looking at for sure.