It seems that there is a fairly commonly used Chinese movement (the Sea-Gull ST16) that
is being used in a wide variety of wristwatch brands. Some of the specs include the following:
40-hour power reserve
21 jewel automatic skeleton movement
water resistant to 165 feet
solid stainless steel
Exhibition back (shows decorated rotor & 'blued' screws)
I picked mine up from a Buckle store in a rather beefy "antique copper" case and band, and
after researching the markings on the rear of the case, found out the info above. My particular
watch seems to run about 10 seconds fast over 24 hours.
For the most inexpensive version I found:
http://www.walmart.com/catalog/product.do?product_id=6562454I believe this is just the movement itself, with no case, band, or even hands:
(scroll about 3/4 page down, Chinese Automatic Movement HZ2189)
http://www.ofrei.com/page1119.html