Four boxes for $30.00? Depends on what they are. Winchester AAA at a little over 7 a box isn't overpriced. Definitely not a deal, but liveable. If they were standard game loads or the old field and clay ... that's pretty steep.
I have known a goodly number of black people. Went shooting with a few. Most were no skeet players, trap shooters to the last man. And, I've never seen anyone shoot trap with anything other than a twelve. I don't believe that I've ever met a black that owned a 28. Interesting. Could they be straw buyers for some eighty year old white dude, on his way to shoot a round of skeet?