It would be better to get a "branded pc" with on-site warranty if you are not confident in trouble shooting PC fault. Carrying the PC down to shops for "repair" and having to spend at least 20 bucks excluding parts can be quite troublesome...............even if you have a car.
I was trying to build up my own DIY PC sometime ago, but realised that the total price was only different by 50-100 bucks. If I buy the "branded version", I get a "full set" warranty for 3 years that saves me the problem of going to different agents just to get a couple of parts replaced. I had the fortune of "using" the warranty recently and the service team was quite helpful in arranging an appointment and service was fast.
And the best of all is that my warranty will still be honored if I change a couple of components here and there, graphics card, ram, u name it, they will still honour it.
For me, the choice is clear, I will go for "branded" PCs.