St. Paul Street, the oldest road in Montreal
Alexey Skripanev—Alamy

In economics, you learn that the more people want something, the more expensive that thing becomes. Unfortunately for travelers, the law of supply and demand applies to vacations, too.

That means traveling to a popular tourist destination like New York makes an expensive cosmopolitan city more expensive. The same goes for international destinations like Paris, where the City of Love shows little affection for your budget.

Read: The Best Tourist-Friendly Vacation Spots for People Who Hate Tourists

If you wait until the crowds thin out, you'll return home with a fatter wallet. Of course, that means knowing where to go—and where to avoid. Consider this a tour guide to great destinations with fantastic prices.