Not really. I think it's a way for Ducasse to annotate his recipes to pass them around his various restaurants - and of course for training purposes. I'm just the sort of home cook who takes the occasional pleasure from trying something a little more involved.

Is it expensive? Not the book, but the ingredient cost of the recipes you tried at home. cost/yield?

No - but it all depends on how you approach what you're doing. In the case of the veal jus, I had four pounds of veal shoulder - one of the cheapest cuts of the animal. The other ingredients are veg, water, and a little veal stock (made from bones - even less expensive than shoulder).
(And by the way, once I had siphoned off the jus, I had the makings of a great veal stew for dinner - so it paid for itself twice.)
But placing truffles as an inhibition to this kind of cooking is ridiculous. If I want to do a duck dish, I can buy a supermarket duck for 5 pounds sterling. But for fuck's sake, it's going to taste like a five pound duck.
If I do my research, and find a duck hand raised, organic and free-range, it's going to cost me a lot more. Now for a thousand bucks - which one do you think will taste better?
For me, the point of getting into food is to find the best ingredients possible - not buying the most expensive for the sake of them being the most expensive - but the best for what you can afford.
I can go and buy a chicken reared in Bresse for around 24 pounds. Alternatively, and with some work, I can start to research alternatives, and I discovered (along with many others) a chicken raised in England under the Label Anglais tag, which is less than half the price (around 10 pounds), and equals the Bresse bird in flavour (according to all of the Michelin 3 star restaurants in this country). But the point is not the price - the point is the looking. The discovery. Finding the best you can, and doing the best you can with it.
"Gimme a pig's foot, and a bottle of beer..." Bessie Smith
Flickr Food"111,111,111 x 111,111,111 = 12,345,678,987,654,321" Bruce Frigard 'Winesonoma' - RIP