Seriously... I got her a popcorn popper for Christmas and could have saved all that money (ok, not a lot) and done this.
1. Take a plain brown sandwich/lunch bag and open it up.
2. Add a half cup of popcorn kernels into the open bag.
3. Fold the bag closed at the top two times over to seal it all in. Don't use tape or staples. Melting adhesive and sparking metal might cause this to fail.
4. Microwave it all for up to 3 minutes. Use the "Stop everything if you hear less than a few pops every few seconds" method of timing.
5. Watch for steam as you take it out and enjoy!
HINT: add butter or salt of plain isn't your thing ;-)