Correct, I will reformulate that: if batch #3 arrives with difficulty higher than lets say 35m, they won't even break-even IMO.
Even at 35 million they'd break even in
46 days (4-unit with extremely conservative power costs as well).
You are calculating break even in USD... but the Avalon B3 was purchased in BTC. Looks like it would take about 90 days at 35M to break even with no power costs... those BTC, assuming the average difficultly over those 90 days is 35M (I bet it averages higher difficulty). If there was no risk... it wouldn't be any fun eh?