Bandwidth and memory usage is something I don't know how to find out myself. I have asked prgmr support about my bandwidth usage, but again no response. How do you estimate yours?
I like vnstat: http://humdi.net/vnstat/. It's easy to set up and has almost zero overhead. I have it send me an email from cron estimating monthly usage once a week. It won't break things down per-process, per-port, or per-remote-host, but I haven't found a nice tool to do that yet.
Thanks, that looks useful. I will give it a go.
A good VPS host has the infrastructure to tell you this within 24 hours of finding out.