User blog comment:EthicsBuster314/I need help choosing a world/@comment-24435881-20140613015423/@comment-11372432-20140613021753

Try to start with a trial deck. There are 3 currently, which are based on Gao's dragons, Armorknights (Danger World), and Jackknife Dragon. Two more are coming on July 4: adventurer (Dungeon World) and ninja (Katana World). Ancient World can be cheap since most of their support is in the only extra set. Magic World is the most expensive as it lacks any cards outside of main sets, Danger World hasn't had any support since set 2, and due to the sheer number of cards Dragon World is likely the cheapest, even getting its own set filled with only Dragon cards.

And do note that there are still two worlds that have been revealed, but no cards are coming soon: Hero World, based on aliens and robots, and Legend World, based on legends and myths. So if those catch your eye, you may want to wait until those come out.