Earlier this month, Marathon Oil agreed to spend more than $1 billion on acreage in the Permian Basin, the very hottest place on the planet to drill for oil. On the same day, it announced the sale of other properties 2,000 miles due north in Canada’s oil sands, a significantly less popular place to invest right now. Shareholders applauded, sending Marathon’s shares up 8% on the news, but the price of the company buying its unwanted…