Replacing Ballast components is quite simple. You can buy 'ballast kits' from your local electrical supplier. The kits come with A transformer, capacitor, and if you have a HPS, an ignitor. Just make sure you get the right wattage and voltage. most ballast replacements are 'tri-tap' meaning they can be wired for three different voltages. just make sure its wired the same as your supply.
If your comfortable following simple wiring diagrams then i say go ahead and replace the ballast. There are little wiring diagrams printed right on the transformers when you buy them. Its easy.
I buy all my ballasts as 'replacement kits' actually. I make stealthy housing for them like old PC towers and gutted receivers. then wire them myself. Wire is cheap, three prong plugs are cheap, ballast kits are cheap, and metal housing is cheap. but hydroponic/professional lights are expensive as hell!!! i dont get it