Jeff Carver commented:
  "If you find a source for a inexpensive fluorescent lamp let me know."
  I love research, and I promise to report any interesting findings I 
encounter.

  "How come you can buy a small fluorescent lamp for 120V for $9US,
but have to pay $35 for an RV one of the same size?"
  I could speculate with the best of them about production scale 
economies, but the truth is, I don't know.  There's a major importer of 
12 volt flourescent fixtures about a hundred miles away from my Orlando 
home and stopping by to harrass them might be fun.  Again, don't worry 
about me tending to be too shy to ask pointed questions.  More if I do.
 
  Cheers,
  John Wakefield