It's a pretty sure bet that any inexpensive shop light fixture will come with an even cheaper ballast. And again, it's another pretty sure bet that any replacement ballast will be of a much higher quality. At Home Depot, at least the ones in Minnesota, they only carry American made replacement ballasts. If you shop for a new ballast, it's important to know what kind you need. Although both T8 (more energy efficient) and T12 lamps (less energy efficient) have the same pin configuration, they are usually not interchangeable with any given ballast. If the replacement ballast you buy comes with more wires than your original ballast, there should be directions included on how to hook it up correctly. But it is easier to just get a ballast with the same number of wires as your original. Its best to bring your original ballast with you to the store, so you know that the new ballast will fit into the old fixture. They are not all the same shape. Get a rapid start ballast, not an instant start ballast, if the unlikely option presents itself.
Electronic vs Magnetic Ballasts
--- Both types are directly interchangeable, as long as they are specifically for the same lamp configuration.
--- Electronic ballasts are more energy efficient.
--- Electronic ballasts are more adaptable to different applications and fixture types (i.e. number of lamps per ballast, and series or parallel hook up).
--- Electronic ballasts may produce radio frequency interference if the ballasts operates within that specific frequency range (rarely problematic).
--- Electronic ballasts do not hum as magnetic ballasts often do.
