Batteries Plus Bulbs

I went in to get 2 batteries for my car key fobs. The guy was nice and fast, but when I asked if I could have bought the batteries and put them in myself for 1/4 of the cost he laughed at me and said "yea." I jokingly said thanks for helping me save money and to that he said, "That's not my job" while he was still laughing. I am all about shopping local and going into the store, but . will not go back here