As announced on Major Nelson's Twitter, Virtua Fighter 5 Final Showdown will be free to Xbox live users from July 1st to July 15th.
Because the game is backwards compatible on Xbox One, this means that players on either console will be able to purchase the game for zero money, provided that they are an Xbox Live subscriber. This version does not include costume DLC.
On July 1st, you should expect to see a surge of players trying out the game for the first time. Feel free to point them to the Dojo if they seem interested in learning the game!