Where can I find the uncensored Mishneh Torah online, or cheap in print?
Mechon Mamre is the best online version. It's based on Yemenite manuscripts. The one-volume version published by Yeshivat Or Vishua in Haifa is the most accurate published edition. The version that appears weekly in the Chabad "Devar Malchus" is excellent as well.
Not exactly sure what you mean by "uncensored," but you could try the version on Mechon Mamre.
Other good uncensored versions include Rambam Le'Am printed by Mossad HaRav Kook, the Frankel edition of the Rambam, and the Rav Kapach edition. The Frankel edition includes extensive notes on the various textual differences; Rav Kapach simply gives you the Yemenite version. The single volume edition mentioned previously can be found here. Online there's also a WikiText version of the Mishna Torah. You can read about their editing policies here.
The best and most authentic version of MT is the one put out by Mifal Mishne Torah. They rely heavily on the Kapach manuscripts (which avoided the problem of Christian censors by being in Yemen), as well as several other manuscripts, at least one of which was signed by the Rambam's own hand. I had the opportunity to talk to one of the project leaders and he told me they spent about 15 man-years working to get the text of MT as precisely and accurately as possible. Their methods and work are impressive to say the least.