Uh no. First of all, yes, it's twice as much. And secondly, what existing monitor keyboard and mouse? It's an imac. built in monitor.
edit: And it's not about getting so much further ahead. It's about playing with electronics, which is what I do.
Also, I don't need a fast, brand new, mac. This is the first mac I've ever owned, so I'm going to get the most out of it that I can before moving on.
Edit again: Besides, getting the mini would defeat the purpose of having an all-in-one imac now, wouldn't it?