I saw this on "the other forum", a site where you can order Bauer replacement keys for your RV. You must have the key number. Since I lost one I ordered two today, 2.50 each plus shipping, but they do not tell you how much shipping is. You get an invoice with the keys when they arrive but not when you check out. That was a bit different then most e-tailers. They have regular snail mail as well as overnight UPS for emergencies.
http://www.bauerproducts.com/replacementkeys.php
http://www.bauerproducts.com/replacementkeys.php