The Paris Museum Pass costs €78 for 6 days and everyone recommends it, but I did the math and most tourists lose money. You need to visit expensive museums to break even — Louvre (€17), Orsay (€16), Arc de Triomphe (€13), Sainte-Chapelle (€11.50) near Notre Dame.

Where it actually works: if you're visiting 2-3 major museums per day and using it for skip-the-line access during peak season at Pyramide entrance. The time savings at Louvre and Orsay alone can be worth €20 in convenience around Châtelet area.

Where it doesn't work: casual museum visitors, people spending lots of time at free attractions like Luxembourg Gardens, anyone visiting during off-season when lines shorter at République area museums. Many smaller Marais museums are under €10 or have free student rates.

Alternative: buy individual tickets for Louvre and Orsay, spend saved money on better meals in Saint-Germain bistros.