Here's an equipment catalog:
http://www.earlytelevision.org/rca_b...pt_prices.html
But, that would only be part of the story. A television station would hire what we would today call a system integration vendor. It wasn't unusual for that vendor to be a major television equipment manufacturer, which is how you ended up with TV stations with all RCA equipment or all GE equipment. They would come in and put the whole thing together from spec to install for the customer, so that would have a cost.
Then there would also be land for the transmitter, and a custom built studio, etc.
It's could be difficult to figure out, although sometimes the stations themselves would say "our new x million dollar facility" in their advertisement literature, so that might be a rough guess as to the total cost.
David