Amazon has announced plans to expand its “ultra-fast” 30-minute drop-off service in dozens of cities across the U.S. . ​ The service, known as Amazon Now, is already available in a number of major locations including Atlanta, Dallas-Fort Worth , Philadelphia and Seattle . ​ On Tuesday the online retailer said it would expand the offer to tens of millions more customers by the end of the year. In a statement, Amazon said the service was being “rapidly expanded” in dozens of cities, including Austin , Houston, Minneapolis , Orlando, Phoenix , Denver and Oklahoma City .​ However, unless you are a Prime user it comes with a significant delivery cost. Amazon is rolling out a 30-minute delivery service named Amazon Now in dozens of US cities (Amazon) Users without a Prime membership will be charged a $13.99 delivery fee per order, compared to $3.99 for Prime members. ​ An additional fee will be added to smaller orders valued below $15; an extra $3.99 for those without Prime or $1.99 for members.…