I saw the entire Disney Infinity Gold Collection was listed on Steam at $14.99. This is a great value for the entire franchise including all games (1.0, 2.0, and 3.0 Gold Editions) with all content such as every character, playset, and power disc unlocked.
Be careful not to buy the individual games as they are currently $7.49 each for the first two and $14.99 for the third. The real value is buying the whole collection at just $15. As Disney servers are no longer up for this game as of March 2017 there is no online support or downloadable community created toyboxes, just local gameplay.
EDIT: Each game is single player only
. Also the following is NOT included in Disney Infinity 3.0 Gold Edition (Finding Dory Playset, Marvel Battlegrounds, Time, Alice, Mad Hatter, Nemo and Dory)
as production on PC had ended in January 2016. -thanks megazone23