There are a ton of factors that will influence whether it is a good idea or not. Price of feed, labor, weather, your market, cost of pasture, infrastructure, scale... are just a few. Every operation has to run their own numbers to know if it will generate a profit for them. Even then, not every one will agree the juice is worth the squeeze because every one will have a different number for "worth it".
I know it's cool to talk these gross numbers on the enet or down at the coffee shop but it doesn't cut the mustard if you ever have to be accountable to any one other than yourself.