Walmart offers the Oreck Commercial Orbiter Floor Machine for $244.76 with free shipping. (Amazon charges the same price.) That's $4 under our mention from a year ago and the lowest price we could find by $55 today. It features 175 RPM, a 50-foot power cord, and is suitable for use on wood, vinyl, tile, and other hard floors.

Update: It's now out of stock at Walmart; however, Amazon still offers it for the same price.