I have sometimes ordered the parts, but I don't think I am very handy, and sometimes cause more problems than I had originally! I prefer to buy the part if I can find it pretty cheap, and then have a professional do it!
I feel this way about cars. But I'm not sure if buying a part and letting the professional do it works for me. Most often, I consult the professional and they tell me what to buy, and then I buy it. If in doubt, I would ask other professionals.
What happens is, I get expert advise. Second, cost goes down because these professionals know where to buy the best deals. Third, a few times I get something for free or half the price. They happen to have a spare item that gathers dust and they want to get rid of it.