Walking Desk Lifespan Treadmill TR5000 DT. Great condition treadmill is designed to convert a standing desk or table into a "walking" desk. It's a little weird at first but if you work at a computer it's a great way to burn some calories and improve your posture. Pretty soon you get used to it and don't even realize you're walking several miles a day. Unfortunately I am moving down to the lower 48 and bringing a heavy, bulky treadmill is not worth the cost. The treadmill was bought a couple of years ago for over $1200. I'm selling it for so little because I'm trying to sell it quickly.