Imagine what 426,000,000,000 one-dollar bills look like. Then imagine people spending those individual paper bills on beauty products. That’s what they did, according to Yahoo! Beauty:
The writer is so funny! She probably doesn’t even realize what she wrote, as opposed to what she meant. She meant an amount of money, which is singular. So even though it looks like a lot and it looks like a plural, $426 billion is singular and takes the singular verb was spent.