Most people hunt for Washington DC hotel deals the wrong way. They search for “cheap hotels in DC” on a Tuesday night and book the first $189 room they see near the National Mall. Then they pay $45 for parking and $30 for breakfast and wonder why the trip cost double. DC hotel pricing is predictable once you understand the calendar. Congress recesses, federal holidays, and convention schedules move rates more than any coupon code. A room at the Marriott Marquis can swing from $149 to $499 within the same month. The deal isn’t a secret website. It’s timing plus…