Recent research reveals the payments (per opera performance) that Lehmann received at the Metropolitan Opera. You’ll see other well-known singers of the time, and the amounts they were paid. Remember that this was shortly after the Depression. Also, the dollar in 1935 is worth about $22 as of 2022.
1935: Lehmann: $700
Rethberg: $900
Pons: $1000
Flagstad: $550
Melchior: $900
from 1936-on (the data is a little confusing), Lehmann was paid $750 ($16,500).