I could host with my current hosting computer, but it won't be as fast, but I might still make the moneys.
The idea for having a separate server (like the one I suggested above) is that you can host your servers 24/7 without having to disturb your normal use of your current computer. If you hosted the servers on one computer, its more likely that the clients would lag and/or the server would crash.
Come to think about it, even charging $15/month for a BL wouldn't be too bad. So that would be $360 a year.
I wonder if a Quad core PC would allow you to run 4 servers.....hmmm...