David, if your know how to edit audio, and if you happen to have a digital piano, there is a simple trick you can use to get great quality at virtually zero cost.
All you need for this is a reasonably good "mono" microphone and two earphones. If your digital piano doesn't have an internal floppy disk drive, you'll need also need a midi connection with your computer.
This is how you do it:
First, make a midi recording of your performance. If you don't know how do to this, I'll be happy to give you more details - it really is very simple, especially for someone who already knows how to edit audio.
Now, connect small earphones into your digital piano. Don't put the earphones in your ears! Instead, place a reasonably good "mono" mic near the left earphone, and mask the right one with something soundproof.
Playback the midi data on the digital piano - you are, now, effectively, recording the left part of the would-be final stereo recording.
Now repeat the same procedure with the right earphone, and don't forget to mask the left one while recording.
As a last step, use an audio editor program (which I assume you already have) to mix the two parts into a single stereo wav file. Take great care to ensure that, in the mixed file, the left and right parts are in-sync: Even a 1/10 second delay will give rise to an easily noticable "echo" effect.
If you follow all these steps correctly, the result will be a great-quality stereo recording of your performance.
I know that this method sounds way too crude to give good results, but from experience I can tell that you it works! And this method also has the advantage of being totally independent on the acoustics of the room you're recording in.