Answer: Consider the benefits and the costs-- not necessarily the money, but the time, effort and sacrifices that may be involved. Will the desired outcome be worth it?
Explanation: It is not always about the benefits to me. There are other people involved. Will the plan bring benefits to them? What might be the consequences not doing something?
Sometimes it's a choice between good alternatives. Someone reminded me: Don't let the good stand in the way of the great.
So what brings the greatest benefit to the most people? Is it practical? Affordable? Sustainable? Does it increase love among the people involved?