As far as I know they are, Tommy. Maybe a year or so ago somebody asked about this and Carbking provided some information, as I recall. I don't think it was as much about buying them as just some venturi size, jet information and such, however.
I don't know about the cost today. The last time I looked into buying one was around 2003 and while they were available locally at that time, I couldn't afford one then and so I doubt I could afford one now.
