Well, the price is "not bad" from some perspectives. I see on the website that 40 nights of lodging starts at 2290 pounds, which is about $3800 dollars. Rounding that comes out to about $100 a night. Though private accommodation on the norte is undoubtedly more expensive than on the Frances because of all the tourist towns it passes through, the kinds of places you will be booked in are undoubtedly going for less than half of that, in some cases a lot less than half.
I have reserved and planned stages for friends on the camino, and I know it is a very time consuming endeavor, but that seems to me to be all that is added by this company for that price. So if it's worth it to you to double your accommodation price by having someone else do the reservations, that's of course up to you. With a Spanish phone and a guidebook, you can preserve the flexibility others have mentioned and stay in the same places at at least half the total cost. Others can correct me if I'm wrong about prices on the Norte (I haven't walked it since 2006, I think), and I don't know if this is a standard tour company mark-up, but I personally wouldn't pay that amount to lock myself into an itinerary in order to save making a bunch of phone calls from the Camino. I mean no criticism of those who do want to spend that, it's all a matter of what it's worth to you.