We have tested FileMaker Server is some very humble configurations, and while FileMaker Server 11 will run on almost anything. It is logical to assume that future versions of FileMaker Server will require additional resources. My advise is to use vmWare Player (free) and run a virtual machine on your 'real computer'. FileMaker Pro will see it and a unique machine with a unique IP address and it will have it's own operating system; so it truly a two machine configuration.
Another appraoch is to use a hosting service like Worldcloud (shameless plug), to host a single file is $12/mth and we don't host with MiniPCs. Even with a MiniPC, you would still take a couple of years before you used your beak-even point, plus our approach required no money up front, and you can quit at any time. If you are interested in testing one of our servers, I can give you a free 30 day trial...
Thanks for that Joe.
You've helped me out with 2 viable alternatives.
I didn't know about the vmWare aspect, sounds very interesting and I don't mind the 'shameless plug', will have a look at your website.