No, I don't think anyone has ever gotten black balled here. At least I never got told. Your question about feeders in the NY, NJ, PA area is kinda specific. I don't know of any. Most frozen feeders have to be shipped overnight with dry ice in styrofoam, hence the cost. You are paying for shipping the dry ice. Why not raise your own? Thats what most of us do here. Before I did that I bought frozen from G & G rodent farm in FL. You can try them. Often when ordering frozen there is a sweet spot in the pricing where you can get a couple hundred more without getting over the next weight/price limit for shipping. Shipping always seem to be about half the cost of buying frozen. If you belong to a local herp club or have some buddies near you, you might ask around about splitting an order. Raising your own is the cheapest, and if your animals can eat rat pinks, I think rats are easier to raise than mice.
Good Luck
DeMak