budget, resource(s) and schedule
budget includes: $ and energy;
resource(s): he and you, or others;
schedule: may include opportunity cost
then, do your calculations with this formular:
How much is too much, too much is how much...“好妈吃” is “2妈吃”, “2妈吃” is “好妈吃"?
http://web.wenxuecity.com/Search.php?SubID=career
have fun!