places go with the pint and quart pricing system because in most counties selling by the pound requires a certified scale the people can see and a printable weight receipt.
At my place we sell by small, medium and large. Small being around a 1/3 of a lb, medium over a half, and large right around 3/4lb. our prices are 6, 11, 15 respectively. We also do sandwiches at 10 with a side. 11 with french fries or onion rings.
Looking at the first menu posted, $10.99/lb and $39.95 per whole boston butt. That's LOWWWWW. At least for what I pay for my meat. I'm a high volume purchaser and I still pay right around $2/lb for our boston butts. Just in food cost's i'm at $4/lb after cooking loss and I still haven't factored in cost of the cookers, labor, rent, electricity, rub. I wish I could do it cheaper, but if I want a profitable restaurant and not a total loss, I had to price accordingly.