Right it seems like convenience is a huge factor. Come to think of it, the way someone values their time might factor in. Someone who makes $60 an hour for each hour of work he/she does can fall into two general mindsets. The first being doing housework and the other paying someone else to do it for them. Paying someone $100 for two hours of work would be a good use of money but if it was $200 for 2 hours of work, then the calculated person would do the cleaning themselves because that would be the most valuable use of their time.