Saudi Arabia already floats on petro-dollars, and while 16.5 billion dollars might be big money in our eyes, it would be a drop in the bucket compareid to their oil based revenue.
Their oil revenue is alleged to exceed 1 trillion dollars this year - 62 times as much as they'll make from the pilgrims.
I bet Italy makes quite a bit from Catholic tourists doing the rounds of the Vatican, and Israel wouldn't do too badly from the religious tourists either.
The Moslems go to Mecca because they believe they have to - not because Saudi Arabia wants to make money.
This was one of the reasons Saddam Hussein had to be stopped when he invaded Kuwait. If the West had allowed him to invade and keep Kuwait, he'd have turned on Saudi Arabia next. He'd have had access to Saudi Arabia's oil, but not only that, he'd have gotten control over Mecca. If Moslems want to get to heaven, they're expected to make a pilgrimage to Mecca.
From that time, if you wanted to go to Mecca, and therefore heaven, and if Saddam Hussein thought he could use you, there'd have been a condition attached. "Right boy, you want to go to Mecca? Then you'll do what I tell you."