Around here, A Body 8.75" housings are like gold... and if you find one somewhere else and have to have it shipped to you, that's expensive, too. We got the '66 B Body rear end with a 742 third member, drum-to-drum for $240.00; no shipping. I don't remember how much the wheels were, but the cost of the wheels and complete rear end were cheaper than an A Body housing around here, I am pretty sure..
Maybe where you live, they're cheaper. That's always a possibility.