hosted-projects.com offers Subversion, Trac and Bugzilla hosting for $7/month on their smallest plan, and less if you pay 3 or 12 months in advance. After repeated failed attempts to set up Trac on my web host or my Mac (lots of dependencies), I finally decided it was worth a try.

hosted-projects.com's administrative interface is scarily thread-bare, and the redirection to the German Paypal site is a little surprising. But everything works as advertised, and set-up is virtually instantaneous. You can even try it for seven days before paying.