I had planned out pretty much everything with one (1) exception: I had not considered that I would want/need a security system. I attribute my ignorance on the subject due to the fact I have lived "in the woods" for 35 years and I thought that TV was crime-free. Yes, I was naive, but I was happy in my own simple world
But when we arrived and a rash of break-ins happened, we purchased a system and have monthly fees that we had not planned on. So to the question of the OP, other than that issue of security, other expenses we had estimated have been appropriate.