I just bought a Edge 500 used on eBay for $160. Says it was only used a few weeks. We'll see.

I already have all the sensors I need. I believe the Edge will work with any Ant + sensors. So that's cool.

If you want GPS there really is no alternative to Garmin. They really have the market cornered.

The Forerunner will do Cadence by the way. You don't really need cadence, but I like having that data.