Build your own PC!
Jeff Atwood has a great series of posts regarding building your own PC.
I have not built my own PC from scratch in a decade but I completely agree with Jeff that you should do it. You get better value for money and a system that is tailor made to your needs. But even more important, there is nothing like learning by doing. I freed up space, increased my WAF, and had some fun this spring by scavenging several old PCs and putting together a decent PC which I donated to the local school.
My "server" at home has gone through endless changes and urgent hardware changes after I decided to host my domains at home. I have learned a lot about hosting, mail, DNS, hardware, web and security. I consider myself lucky as there has only been one "incident" since I started hosting my domains at home. I was all my fault as I had created a test account on my SMTP server with password "test" that I forgot to delete after my tests, essentially creating an open SMTP relay. It did not take long for hackers to break the password by trying common account/password combinations and spam the universe. Luckily I was at home and noticed the abnormal internet traffic and closed the hole quickly but thousands mail was sent from my IP :-(
Lesson learned. I wrote simple web honeypot is also useful if you decide to host your own websites.
P.S. Do not expect to save money, and especially not time, if you decide to host your domains at home. Electricity alone costs more than renting resources on a Virtual Server, at least in Italy.