I get the same offers from CI. Nobody can say Christopher isn't a persistent marketer.
At $17.50, it might be worth the money as a good read to fuel the imagination but I haven't felt compelled to add yet another cookbook to the collection.
One thing they don't specify in the mailings is which edition they're offering at that discount. The second edition has much more content than the first. It's possible the discount is on the smaller first edition.
Looking forward to hearing from anyone with this book.