I think your idea of affordable and mine are a little different. I have a wife, two kids, two cars and a house to pay for every month. Not to mention a two week vacation to Scotland coming up in May. Then there's the matter of the new fencing for the yard...

Short version: I have limited money for "non-essential" projects.

I actually have that enough storage space on my existing machines, but they're multi-tasking pretty heavily. The two laptops are my wife and my day to day machines for email, browsing etc. That just leaves the two desktops. One of them is for the kids and has been heavily firewalled so it wouldn't be suitable as a mediaserver.

The newer machine probably is sufficiently powered and it might have enough disk space (just), but it also functions as the print server and runs a lot of the more memory or processor intensive programs (image processing or video conversion, that sort of thing). We can remotely log into it from our laptops which makes it ideal for this function.

If I'm going to spend money on a mediaserver I want it dedicated to that function and I want to set it up so it can stream to any of the three tvs in the house. I really don't want a hack, that's basically what I have, I want a complete flexible solution.

It's all doable but without a dedicated machine I don't think it will be satisfactory and I don't have a budget for a new desktop this year.

Plus my wife would probably complain.