When I was in college I got it into my head to learn to juggle clubs. The only jugglers I had seen were on TV and I thought they were using wooden clubs. I found some old bowling pins and set about teaching myself to juggle. What I taught myself was how much it hurt for solid wooden clubs to slap into your hand after a fast spin.
It was years later after I actually was able to touch a jugglers club that I discovered they were lighter and not solid wood. Many years after that I bought some clubs along with an instructional book off the internet. Every summer I pull them out and mess around. Still, they were expensive (I am basically a cheapskate!) and if you are just looking for a cheap alternative, how about making them yourself. If I had seen this tutorial 6 years ago, I would have made my own.
If you are looking into juggling with a bunch of kids, this is a reasonable alternative. Could be a fun project.
[Image captured from Juggler.org: How to make your own juggling clubs: http://www.juggler.org/diy/clubs.shtml]