That's the problem. Folks who like them are most likely like me: They need the device one time, use it, and then re-sell it. Cycle repeats itself. Folks buy them up quickly. So, it's pure luck and timing to find one in time to buy it used. Buying it used for $400 or less, and using it once, and then reselling it for about the same amount of money is a win-win situation. One can completely refurbish their car's undercarriage to like new or better than new without the royal PITA factor.