Is it still a saw if it only has one tooth? Lenox avoids the issue by calling this tool a hole cutter, and its design evidently offers some really cool advantages over normal hole saws. For one thing, the cutter works best with low torque and high speed. And it’ll cut holes that aren’t perpendicular to the workpiece!
I couldn’t find any video demonstration of angled hole-cutting, only this picture which isn’t even on Lenox’s site. Sizes run from 1-3/8″ through 6-1/4″, and pricing varies by size — I found the 1-3/8″ for as low as $4, but the larger sizes run well over $100.