The first part to good 'calculativeness' [for lack of a better word] is understanding where the line is - the line that separates you from the manipulative kind. There's multiple factors to what defines the line. The first being - resources you can use. The best weapon of the calculative person is frugality. Think before you swipe seems to be the apt'est' slogan. You make the biggest step over to manipulative, once you assume the resources available include people around you. Friends, colleagues, neighbors etc. There's no worser feeling than of being manipulated by the people you consider to be your friends.
Another is the ability to control your calculativeness. The end goal to any wealth accrual plans is happiness. Make happiness a part of your calculations - a major part of your end result. Its a personal choice as to whether you want to give up a lot now to be more content later. But remember there are things you are giving up now, which will not come back. Maybe being able to buy that house a few years before you would have bought it, because you gave up spending time with your friends for a few years will feel good when you get the keys to the house. But remember, the few years lost might never come back. People move away, grow farther apart and the kind if you are not part of their daily lives.
I guess, there's a huge list in the making if i continue on. But I don't intend to go further. The point i wanted to make was, Be calculative not manipulative. And in being calculative - be so considering there's cons to it.