I could recommend a free Linux software called "SME Server". you can d/l it from www.contribs.org.
If you are a bit tecchie, its worth a punt.
It will run on any half decent PC and can be used as an evaluation server while you noodle with Moodle and then, by adding a second ethernet card, with a tiny reconfig (not hard to do), the same system can become an online server (yes, it supports DynDNS) and can be a useful way to get a Moodle up and running.
They even have a module for Moodle (http://wiki.contribs.org/Moodle) which makes the install a snip.
Other than that, I use Netpivotal - for under £60 a year, you get ample hosting AND free apps like Moodle as addons. You even get a free domain.