There have been other discussions here about hand-plucking, with tips to make it easier. Or read http://thedeliberateagrarian.blogspot.com/2009/02/how-to-properly-scald-chicken-my-never.html I find it makes a big difference if you tie the bird's legs together and have a place to hang him by the tied legs after he's been scalded. A place that has him at about shoulder height, so you have both hands free to swipe the feathers off. I can do mine in about 5 minutes, most of it is as easy as cleaning the lint out of the dryer trap.
If you MUST have something mechanical, start with a cap you can make to put on the end of your electric drill, it will work almost as well as this $400 machine.