Monkey, many here do not build their own, as they do not have the expertise, nor someone to show them how to.
Sure, if you know how to, its easy, and you could use old parts off the older system (which I believe, Yahtzee will be giving to his Bro, so he does not have to share...)
But, if you have no clue, and no support for your first time building, it can be a mess.
I have floated this idea past Yahtzee before, and he does not have the knowledge, nor the back up to do it. So he wants pre-built and little hassle.