The list of things I pay money for, and the list of things I can ask my friends for help with - are largely seperate lists. 

The reason to spend money, is that I cannot do it myself, and my friends won't help me. That's the point of money. 

My friends nor I can make a desk from raw materials, so I pay money to buy a desk. My friends nor I grow our own food, so I pay for food. 

As such, I don't really see your point about - you wouldn't ask a friend to do this - yeah, that's true for almost anything I spend money on. If I could get a friend to do it for me, then I would, and not spend the money.

Therefore your argument is backwards. Jobs aren't defined by what my friends are willing to do (as your post says). Jobs (that I might be willing to pay for) are defined by what they aren't willing to do.