Like you said, it's supply and demand. If your request is something very specific to your forum, and won't be used by many others, the hacker will more than likely skip it and do something more will enjoy.
Email me (chen@vbulletin.org) if you are interested in custom work.
It's not important, but PHP.net helmed me IMMENSELY. Yes, I had to have the basics of the language down first, but once I did, I learned tons just browing through function definitions.