I guess there's two ways you could look at that:
1) You could have your ultimate goal in mind. Mine being turbo and nitrous at the same time, for instance.

From there, you buy the things you need to build up to it, like a stronger ignition for instance since this is an ignition related thread. Then when you have everything you need, you invest in the final modification and be complete.
2) Or go the never-ending cycle way that most people do (and I almost did) and buy a few parts here and there until they max out the performance of other parts, like leaning out the car because the injectors or fuel pump can't handle the fuel needs so you upgrade those. Then it turns out you need this, that and these as a result of your last upgrade, which in turn makes you need something else, and the cycle just repeats.
So I say if he has big plans for the engine, by all means go ahead and upgrade your ignition because you would eventually have to anyway. Like me for instance, I plan on swapping my auto for a manual sometime soon and I'm going to go ahead and opt for an ACT clutch and lightened flywheel and upgrade my engine internals to prep for turbo, even though I don't need it yet. But I figure I will eventually, so why not just be ahead of the game.