Are you looking to manage the Tomcat system yourself or are you looking to have all of that managed for you?
You can pick up a low end VPS and manually compile Tomcat support into it yourself if you're wanting to do your own management on it.
I don't know of any hosting companies offering VPS and Tomcat out of the box managed for under the $50 range, but there's plenty of VPSs under $50/month that will let you compile Tomcat.