I also have a (precocious) 4-year-old boy. I did read that book, but it was some time ago, so I would have to review it to pull apart its points vs. my mental jumble of all the parenting reading I was doing 2-3 years ago.
Our approach is also centered around give-save-spend. We have a 3-part bank, and any time he gets money (birthday, chores, and he's really good at finding money at the train stop) we discuss what we could do with it, and what balance that is. For a while, it was all "spend," because he was (and is) very into Hot Wheels. But overall, it is surprising how often he chooses save and give as well. I agree that save, at this stage, is goal-oriented spending: saving up for fun on a vacation, or a big Lego set, or something.
To keep down the torrent of wants, we have a (rough) maximum of toys he gets. At this point, if one comes in the house, one needs to leave. This is another give opportunity, too. (or could be money-focused, but we aren't up for a car boot sale nor are they worthy of eBaying)
We don't really give him allowance, because his grandparents spoil him, and his banks don't empty. He is expected to do all of "his" chores gratis: putting clothes away, helping set the table for dinner, cleaning the house, etc. What we did set up as an experiment is to give him a chore to help refill the cat's water, for 20 cents a time. (if done with no spills--10 cents if there are some issues) We do not prompt him to do this--it's when he notices the need. In addition to money lessons, we are interested to see how he does in caring for someone else--a prerequisite for ever getting a puppy, which will take a lot more care. As I said, this is an experiment at this point, so whether we go the pay-for-chores route or a flat allowance will depend on the lessons he seems to need reinforced.