Comment by giaour

Standard grocery margins are usually lower, in the 30%-40% range, and are often much lower for promotional items. Rotating "loss leaders" to get people in the door are standard practice. IMHO that would make it hard to bring an antitrust action against a grocery chain, as pretty much every store engages in a limited amount of predatory pricing as a marketing technique.

50% is the standard retail markup, but it varies by industry.