Mattel released the second wave of their DC Comics 6″ Multiverse figures that are currently shipping to stores. This is the second wave that you will need to form Justice Buster, their new Connect & Connect figure.
Amazon.com has listings of Batman Zero Year (currently $19.99), Earth 23 Superman, and Reverse Flash figure listings. At this time, only Batman Zero Year is available at the $19.99 price, and the others are listed by third-party sellers.