Anyone looking for a decent acoustic guitar microphone for a low price should definitely consider the GHS Original Acoustic Soundhole Microphone. It is designed to amplify the sound of an acoustic guitar, but is nowhere near as annoying as a set of pickups can be.
The microphone maintains the rich tone of my Dean Martin guitar while providing the quality amplification that I need for live performance. It may not be the top of the line, but it is certainly worth the price I paid for it.