How many Roadmaster Harley sportster bicycles were made?

We just recently purchased a Roadmaster Harley Davidson Sportster bicycle off of ebay. They don't make these anymore is about the only thing we know. It is red and a 20in. bike. They were around $300.00 new. We haven't been able to figure out how many were made though, and we are wondering how rare these bikes are? The bike we purchased has the original saddle bags, and we are getting a rear license plate thing with it.