It's not supposed to be this difficult

Well, I've started my diet without actually having finalized what my rewards will be.  Unlike the Colonel, I don't have one army that I am building (see sidebar) so it is not so easy to pick out what I might want to use.  It's clear what he picked: high end supplemental items that go with his army, like Forge World vehicles or army books.  No core miniatures, no fundamental rulebooks, nothing that he needs, just stuff that he might be able to talk himself out of buying all things being equal.
But I'm a (pretty terrible) army hopper, switching from one game and army to another.  It's not really my experience to work on just a single project, despite my admiration for people who can.  But if I just say something like "I'll spend $15 after two weeks of dieting," what is to stop me from doing it anyways?  I buy stuff all the time (the joy of having a job that pays a pretty good income).
No, I think the best thing to do is the following:

1. Pick one army to build up over the next year, buy the core troops normally and save the "special" stuff for the dieting awards
2. When I start running out of steam, switch to a couple of alternative projects like my son's HOTT lizardmen army or the 28 Numidians still in their package
3. Don't buy anything that isn't in the project

That means I will probably be setting aside ideas like doing A Very British Civil War or the Siege of Malta this year.  Now to just figure out what the project will be.

On a related note, today people brought in a dozen Krispy Kreme doughnuts and a chocolate cream pie, but I'm holding strong.