Buyers dislike higher prices, but they do expect them. This month, Dollar Tree stores in the U.S. began adding items in the $10 range. That would have been unthinkable not very long ago. It feels jarring. At the same time, it is also fairly predictable. Sigh. Had to happen, right? Inflation does what it always does. It lifts baselines. The psychological floor price moves up, and buyers recalibrate even while whining about it. That tension affects product makers everywhere, not just in the...