Question:
There is a small grocery next to my house that is a tad more expensive than the bigger grocery further down the block. I know the small grocery needs parnassah. Am I allowed to buy by him and deduct the difference in price from my maaser being that I would have paid a lower price at the bigger grocery.
Answer:
If you could get the same item from the other store and you are buying it specifically in the more expensive one in order to support the poor person, then the difference may be taken from maser money, and it is a very respectable way to give the man tzedakah.
Sources:
R’ Feinhandler, author of B’orach Tzedakah.