Actually the opposite: his pay went down to 0. The pope receives no salary.

His modest daily needs (food, shelter, clothing, medical care) are provided for by the Vatican1. Popes do not accumulate wealth, and usually die in office. It's difficult to even imagine what he would use money for. He has all he needs. He is able to say the Mass, and he is able to serve God and people. He lives in the midst of a beautiful historic site.

Sometimes, Catholics try to give him money, but he just gives it all away.