I've only built a few set of wheels, but what a great skill to have. I completely agree about factory wheels. If only manufacturers would quit upgrading rear hubs (tongue in cheek), I would still have that first wheel set I built back in the 80s. I never had to true it once it left the bench.
Since I'm not a pro, it's hard for me to justify the extra expense of buying components. I make do with relatively inexpensive factory wheels now, and make them last until I can't pass up the next upgrade.