From a US stamp dealer to a Philippine stamp dealer in 1939:
"We have your last price list and note you offer #427 used at $2.20 per 100. We have a supply of these on hand which we can offer you in nice condition at $11.00 per 1,000. If you can use them, send cash with order, or advise through which bank we can ship for collection."
If the Scott catalogue hasn't changed its numbering since, then #427 is the 12 centavos blue Eucharistic Congress stamp of 1937.
The memo sent by postal card is from the Engros Stamp Company of New York City to the Manila Stamp Company.