Yeah, I agree with that -- if you're gonna make a gross financial miscalculation and spend a bunch of money on something that you later realize should have been spent on something else, then better you learn it now when it's a relatively small amount of money and your parents are there to keep you from starving. (Plus, at worst, you've still got new pickups! :)).
My wife's parents and aunts and uncles came out families totally dominated by her all-powerful grandfathers who took care of every aspect of everyone's life -- while they were alive. As soon as these patriarchs died .... well, it is incredible the financial (and other) difficulties people can create for themselves when they're suddenly thrust into situations of adult responsibility with absolutely no experience at being responsible for anything!
Best that people learn what is and isn't a good idea when they're a) young and b) not positions where they can do too much damage to themselves or others!
And meanwhile, you'd best get stuff while you're young that you're gonna be happy with for a looong time. I got my guitars and my bass just after university, and the BKPs for my LP was the first big musical purchase I'd made in almost 15 years!