Via The Points Guy, you can fly across the US in coach for ~$237!
I found a flight from New York (JFK) to San Francisco departing February 4, 2017, and returning February 11, 2017, for ~$237. And a flight between New York (JFK) and Los Angeles leaving March 3, 2017, and returning March 9, 2017, for ~$257.
These fares are valid for travel from January 2017, through March 2017. On airlines like United Airlines, American Airlines, Delta, Virgin America, and JetBlue.
Here are the details. And how to search for deals from your city!