haha, buy what you need....
I can tell you all those extra spaces you pay for, will just end up collecting dirt.
the last house I had, 6000 sq ft, 5 car garages, at most, we use 1/3 of that space.
the current house I am in, 2900 sq ft, it still too big, I think we can get by with 2000-2200 sq ft no problem.
more space you have, more junks you collected, we gave away half the stuff when we move to this current home.