A costly summer sendoff approaches

Persistent pump pain and pricey burgers mean this summer's last hurrah comes with a cost crunch. The big picture: Gasoline prices are almost certain to remain north of $4 per gallon over Labor Day weekend — a heavy travel stretch and the time when midterm election season intensifies. Driving the news: Labor Day gas prices are slated to be the highest on record, surpassing the previous one set in 2012, per market tracking firm GasBuddy and AAA. That's coming off a record-setting August, where…