I am currently running a 4gb PC which I've turned into a Hyper-V server on Windows Server 2008 R2 x64. This isn't exactly server-spec hardware for doing dev stuff in free time. At the moment, because there is not enough RAM to run more than one VM at the same time, I am running everything in one VM, e.g. AD, TFS, Sharepoint 2010, Biztalk - VERY bad I know.
As a result, I am planning to rent a server so that I have the hardware to deploy what I need (TFS, etc). However, if I rent, I will pay for the price of the server itself within a year. Would it be a bad idea to buy a server in an auction of ebay? I am not worried about software licenses as I have Techet/MSDN licenses from Microsoft.