Northwest Outdoor via eBay offers the factory-refurbished Garmin Forerunner 405 GPS Sport Watch, model no. 010-00658-12, for $39.95 with free shipping. That's the lowest total price we could find for a refurb by $10, outside of the offer below. It features a GPS receiver, LCD, heart rate-based calorie calculation, and alarm clock. (It doesn't include a heart monitor.) A 1-year Garmin warranty applies.
Don't need the Garmin warranty? Newegg offers a refurb for $38.37 with free shipping. A 1-year warranty applies, but it's not clear who backs it.