Treadmills are a great way to exercise without facing the wind, rain, snow, heat, or dead of night. Studies say that people burn more calories on a treadmill than any other exercise equipment, because the natural walk or run motion is easier to sustain than the motion of an elliptical, stair climber, or even a stationary bike.
But a good home treadmill is a major expense. You can expect to pay over $1000 for a decent quality home treadmill. Anything below $1000 new is likely to be underpowered or of less-sturdy construction. You can get more for your money by buying a used treadmill. The best time of year to shop for used is in the summer when people are moving or have realized they will never use their treadmill for anything but a clothes rack. But you can try Craigslist or shop at Play It Again Sports in Portland, Vancouver, or Beaverton for used treadmills. They have locations throughout many states.
And now for a LOLCAT:

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How do you keep your treadmill from becoming a coatrack or cat bed?