Having trouble starting engine

1997 Toyota 4 Runner, approximately 110,000 miles, 6 cylinder engine. Sometimes when I turn the ignition to start the engine, all I hear is a single click and nothing happens. There have been times when I have to turn the ignition back to the off position, then try starting it again as many as 3-4 times before the engine starts. Sometimes I take the key out and retry. There are also times when it starts with no problems on the first try. It doesn't seem to matter whether the engine is hot or cold. Is this a bad starter or hopefully a cheaper repair?