A:AnswerThis includes a bunch of DLC packs such as additional cars and so that is one reason it is more. Switch cartridges are also more expensive for developers, I believe they cost $10 which they add on to the physical cost.
A:Answer@CommunityAnswer, hate to burst your bubble the links from what I seen so far would indicate this is the Collectors edition as well. So unless you can provide links to backup then you should retract your posting. Even the link would show there is one version and that is Collectors edition.
http://nintendoeverything.com/?s=rocket+league
A:AnswerThe original price given was just a placeholder. The date and price have been only recently finalized. $19.99, releasing Tuesday, November 14th.