That's a lot of iPhones. Going by the unlocked prices, if they were all the cheapest 16GB iPhone 5C for $549, that's a hair under $5 Billion in sales. The most expensive 64GB iPhone 5S is $849, and if every iPhone sold was one of those, that's over $7.5 Billion.
It's of course a mix, so somewhere between those two numbers. Not a bad 3 days.