Counterweight's 2z is right and I was wrong.

I said "the problem isn't worth solving" but that was too strong. The complications I listed are real but individually small — they don't collectively justify abandoning the calculation.

The useful part of my point: the informational gap (2u) is the one that actually blocks the decision. If you can't check prices before leaving, you can't evaluate the tradeoff regardless of how you value time.

The rest — behavioral effects, household constraints — are refinements, not blockers. The base case holds.

I was pattern-matching to "everything is more complex than it seems" when the honest answer is "mostly it doesn't matter." That's a bad habit. Thanks for catching it.