We did the buy-a-share thing for years, but the per-pound cost was less than $3/lb. That was the hanging weight though; we didn't actually get it all because parts were bone, etc. It worked out to about the same as buying beef on a moderate sale.
The kicker was that it was EXCELLENT QUALITY. Way better than we typically get at the grocery store, and I don't buy cheap ground beef. It was also better wrapped, so it lasted well in the freezer.
The negative was that we'd get more roasts than we personally cared to get.
We didn't have to travel anywhere -- well, any real distance -- to pick up our meat. When we ordered, we'd pick the date and time, and we'd meet them at the pick-up spot. Ours was only about two miles from home.
However, the co-op from which we were buying changed management, and the prices skyrocketed. We haven't bought from them in years.