Salary as stated in Halacha

Hello Rabbi.

The Talmud (Berachot 27) cites a contradiction between the words of the Mishnah that one can pray Shacharit until midnight (Sages) and the Baraita, which states that if one did not pray Shacharit, one can pray Mincha twice, meaning that Shacharit is also timely after midnight. The Gemara states: Before midnight, they will understand that prayer at its time will be rewarded; after midnight, they will understand that prayer that is not timely will be rewarded;
 
My question is: The Gemara’s excuse here is quite strange… Since when does Halacha deal with how much salary you will receive?? How do you understand that??