Yep, right on track. I had one from Radio Shack that cost me about $15. It was an incredibly crappy mic, but it worked. I would spend the extra $$ and get a decent one. My suggestion would be to use something like this
http://pro-audio.musiciansfriend.com...one?sku=277522
I am not suggesting or endorsing this specific mic or vendor. I am merely giving a suggestion as to a way to go. This mic will get you where you need to go. It has a battery power supply so no power from the sound card is needed to run the condenser. This kind of condenser mic without it's own battery is why you have a "phantom power" switch on your PA.