支 usually means support or branch, but here it seems to take on a different meaning. Unless it means they plan the support they use in their life on money? I also tried to replace 用支 with 用之 and 用纸， but neither of those seems to make a ton of sense either.
现代人，有的在金钱上规划自己一生的用支
original document: http://www.bailinsi.net/05wsbl/04wcl/02cswd/05/01/001.asp
用支 could mean expense， i.e. "所用開支"
The complete sentence means:
Some modern people finically planed how they expend in life time.
I agree that it means "expense"
the character 支 also appears in 支票, or cash, it can refer to money
用支can literally be interpreted as money used, money spent, so an expense;) it is a verb+object compound noun
In the context of the sentence and text it can also makes sense to plan one's life according to expenses. Early in the same phrase the writer uses 金钱 which also means money and sets up the topic for the phrase.Later in the same sentence the phrase 何时成家立业 "have a family and start a career" made me think of buying a house and a car, which are expenses people consider in their long term plans, 长远的规划
现代人，有的在**金钱**上**规划**自己**一生的用支**，有的在感情上规划自己一生，不但对于何时**成家立业**，甚至所谓传宗接代也都有了**长远的规划**。
Hope that helps!
