Hi, I haven't heard of such a microphone if one exists...It is possible to hook up any microphone to the Auto-Tune plug-in or rack version and have it in real time this way...As far as cheap replacements for Auto-Tune goes, in GarageBand there is an auto-tuner, but if you're looking for quality you're going to have to spend some money and invest in either Auto-Tune or Melodyne, both of which are great choice in my opinion...