I wish there was but I have played most games similar to this (Star Wars , Marvel Strike Force, Disney Heroes, ect ect...) and they all generally follow the same kind of model, they are super fun giving you tons of energy and progression is super fast then you become energy starved and find yourself getting on for an hour or so a day to use your energy or spending money to keep going. Just like those games, money in raid is best spent on gems to buy energy, rarely do these games offer deals that is worth it for F2P members. There are exceptions though as most of the new player bundles in these games are incredibly worth it and then the deals become rather ludicrous. With that being said I'm still a (mostly) F2P player on Raid.
[edited by a community-manager]