I do my own motorcycle repairs, because I sometimes stray far from the nearest mechanic, and field repairs can be necessary. I also cook a lot, because I have to eat every day and restaurants are expensive.

However, I paid someone to rebuild my forks, and I buy pre-made pie shells. Those things are not worth doing myself. My father rebuilds engines in his garage, but won't change the oil on a slush-covered car. He'll pay someone else to do it.

I guess it depends on how pleasant the job is to you, how often you need it done, and how much it costs to get it done relative to your own salary.