hecks, I have a small farm, so I am probably more versed in this than most here.
I only really have sheep, as most of the other things I produce are consumed by only me, family and friends (fruits and eggs and such)
My sheep however I do take to market.
I make a very very healthy profit, they are hair sheep (so no shearing required), and actually you may know them, since they are named after a Mountain your state, katahdin.
I will use 100 sheep as my point of reference. I only require 25 acres for that (as long as I rotate pastures correctly) and that many Ewes will produce about 180 lambs.
I will keep about 10 ro replace older ewes, and sell the other 170. I will get roughly, 22000 dollars for that (market rates today), and I will put less than 3500 into the entire operation for the year.
Now, if someone is doing that x10 or more, they have a HUGe profit margain, and could abuse this sytem easily.
So, you need a combination of acres/NET profit per acre, etc...