From the never-ending treasure of K C Pingle. He posted the following in the RMIM group (Filmfare July 1957)
Within minutes, he and Vibhendu located the Variety article (March 1957)
So, before Raju Bharatan who cooked up the 25,000 songs claim, we have RK Narayan claiming to Variety that she made $200,000 a month, which the Filmfare then reduced to one-tenth :)
No wonder she was busy defending herself before the Income Tax authorities for so many years for under-reporting her income.
Now You Know!