This was one of the questions that passed through my mind as I climbed to the top of the cupola of St. Peter's Basilica. Admission to the church is free (unless you count the time spent waiting to enter), but if you want a panoramic view you have to pay seven euros, which includes an elevator ride part way up. Then, from the inside of the rotunda, where one can get extremely close to some of the mosaics, it is another 320 steps (according to the sign) on a very narrow staircase with sloping walls to the top, where there isn't quite enough room for tourists to make their way around the tiny walkway on the outside of the structure. Claustrophobes and acrophobes are advised to stay home. Cheapskates can walk all the way to the top, skipping the elevator ride. That is only four euros.
Although the interior of the church is a sacred space, apparently its exterior is not. On the flat roof of the building, where the elevator stops, there are a souvenir shop and a snack bar. Serenely smiling nuns in blue habits work at the store, accepting money for items such as credit card sized and laminated photographs of recent popes, necklaces with crosses that come in egg-shaped plastic containers, a gazillion figurines, snuff boxes with papal images, and all manner of postcards, books and religious objects. Not to mention that the Vatican has its own postal system and sell stamps. I wonder how much they take in each year.
Back on terra firma I witnessed the changing of the Swiss guards, handsome young men in blue and gold costumes who patiently protect the pope while millions of tourists stop and take their picture, at no extra charge.