Dancers are employed by ballet and dance companies, television studios, and film and theater productions. Usually, they work on a contract basis.
Income for dancers varies greatly depending on the type of dance they do, the length of the contract, and whether they work for a small professional dance company or a large commercial one.
My website for the Cool For Cats show on ITV in the 50s and 60s is coming up soon. I've been in touch with Dougie Squires and hope to get pics and names for some of the dancers soon and background...