Best advice I would give, is to know your limitations. I'm all for learning and trying new things. Fixing up and remodeling my old house, I learned what they are.
If you have the proper tools and instructions and your willing to try, why not? You may find it wasn't that hard and saved some money.
Now if it was something major and expensive, say the logic board, and you were unsure, I'd say get it repaired. Know what your limits are.

Just remember, if you can't fix it, then you will have to get it fixed. Find out how much before you even try and see if its worth the effort.