[masraum]

Back when I was poor, I built several computers. Mostly trying to maximize performance for minimal $$$. I then bought a couple of cheap computers (sales, or Dell outlet) because I couldn't buy the parts for the cost of buying the whole thing. My last two computers have been more expensive, but fit criteria that I couldn't manage building my own.

It very much depends upon your goal, but, especially if she's 12, it seems like a great way to bond and her to learn some things. I vote build your own.