I have two geese as well—have you found they help against predators? Anecdotally, we've had no predators steal any chickens since we added them (though a coyote got some goose tail feathers at first), though our neighbors down the street have been decimated by foxes.

Never considered the ROI, but I built a big walk-in coop for maybe $200 in materials. Think that'd pay off with the current price of eggs, if we sold them.