I've been trying to find out what an appropriate primer would be for automotive flip flop paint applied to a fresh alder body. I've read that B.I.N. is a good sand-able primer, but don't know if it reacts with enamels or urethanes.

I called Charley's Guitar Shop to ask about having them do the white-blue flip flop paint, but they want $650 for a body. A custom car shop in a nearby city can do it for $200 to $300.

Suggestions as to primers? Thanks for any replies
Call your "custom car shot in a nearby city" for primer suggestions. Almost anything will go on the wood easily enough, but if you want to know what will react with the specific paint you've chosen, they'll know.
"Flip flop" paint is also called "chameleon paint". It changes color depending upon your angle of view. It's been around for over 30 years. The paint on Stevie Ray Vaughan's Charley lipstick guitar was a white and blue flip flop. It's popular with the hip hop look today. Here's some examples: http://www.google.com/search?q=flip+flop+paint&client=safari&rls=en&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiazr6Xu-7KAhVCSSYKHWJECzIQsAQIGQ

I called the manufacturer, and they have a special primer for it. I don't have a paint booth setup anymore, so I'll have to ask the custom car shop to shoot the primer.