The Paris Museum Pass pays for itself once you've gone into four museums. You can buy passes that are good for 2, 4, or 6 days. All we should need are the 2 day passes. The really wonderful thing about getting these is that they allow you to skip the line at nearly all museums. This can definitely save hours of time over a couple of days. It's good for over 60 museums in and around Paris including the Louvre, d'Orsay, Notre Dame towers, St. Chapelle, l'Armee, Versailles, and Arc de Triomphe. I recommend we buy it either at the airport in Paris or at whichever site we visit first. Ordering over the internet is not cost saving since it costs over $20 to have the pass shipped to the US. You cannot buy it online and just print it out on your home printer.