The level pack is $6.99; Costume packs (only 1 available now) are $5.99; and a Season Pass (Level pack, all 4 Costume packs) is $24.99.
The Level Pack comes with 2 costumes (Cyborg, Cheetah), the Hero Cape power-up, the Wall Jump material / tweaker, and dozens of materials / stickers / objects / decorations -- oh, and the Memorizer, which allows for the saving of progress.
The Hero Cape allows Sackboy to glide by holding R1 after jumping; it's very similar to the mechanic in the Batman: Arkham series. It's highly maneuverable and very fun to use if the level is designed for it, like the Hero Race side level.
The new Wall Jump material and tweaker is really, really good. Whatever surface is activated, Sackboy will cling to it and be able to slide up/down at varying speeds, then jump off at the right time. Slide speed and direction can be changed from +/-200%; so Sackboy can slide up/down, or just stay in place. Jump strength can also be changed from +/-200%.
Wall Jumping really opens up the platforming, IMO, and it is very fun to just create a little course and traverse your way through.