If you want the cheapst to get around your problem try this.

Get any mixer, a small 4 or 8 channel will do. Make sure the mixer has mic inputs.

Get yourself a Y cable from 2 1/4" jacks to one mini jack to plug into your soundcard line input.

Hook up your mics to the mixer's mic inputs and record away!

If you want the 2 mikcs to go to different tracks then just pan them on the mixer.

Hope this helps.