from the folks at Drawing on the Right Side of the Brain?
I think they sell it as a Portfolio which includes the DVD, a Work Book, and all the accessiories for $109.
If you have, how have you done with it? I.e., is Leonardo Da Vinci looking over his shoulder? 
I read her first book many years ago, and have recommended it frequently – not because she’s a really fantastic artist (she’s not) or because it’s a comprehensive guide to all things drawing (it isn’t), but because it’s a good presentation of some basic information and, to the best of my knowledge, it’s the best thing out there.
Worth $100? Maybe. If that’s not a lot of money to you, then sure, why not.
You’d probably learn as much from an 8-week class with a really good teacher, which might not run you $100.