Because it was expensive and it goes against his pride to pay so much money for something he can do himself. Maybe he cared a lot about his self-image as a self-sufficient most-definitely-not-a-spoiled-rich person.
In the article she mentions that she controls the budget, so it was probably over the budget he had to work with.
To be honest, the author's culture is alien to me and I only have stereotypes (TV and movies, mostly) to go on.