Molly: By "perpetual motion", I'm assuming that you mean self-winding? Or, a watch that winds itself using the movement of one's
If that's the case, there are quite a few
watches available. Seiko offers a quartz watch without a battery that uses movement to charge the watch. For pure mechanical self-winding watches, most today are ETA based automatics and run from several hundred to tens of thousands, with remarkably little difference between the lot. For a truly exceptional watch, at the mid to high end, Rolex is a good choice. Excellent Hamilton
self-winders are available for under $300.
Personally, I would not pay a lot of money for any ETA based watch regardless of the brand.
You might also investigate the used watch market where many high quality watches are available.