The actual transducer that attaches to the bottom of the seat can be as little as $150.00 and go up to around $700.00, with a few steps on the way. The more expensive - the more powerful. They need an amplifier to drive them too, and that part ranges from $300 - $1,000. So complete they would range from $450.00 to $1,700.00 depending on the specifics of the application. Hope that helps!