Each God costs 200 Gems if bought separately (though they can be purchased with in-game Favor as well, that will take you a VERY long time) and Gems are worth a varying amount of real money.

Newcomers can start the game with every god available, as well as any new god that will ever be created.

I hope they keep this deal going, I have a few friends i want to play this with and it would suck for them to have to take forever to earn the amazing other gods

This is a pretty good deal if you plan on purchasing gods with gems, and if you already have some gods you will get a refund so you can buy gold/legendary/diamon skin + emotes for your favorite gods, and you can play and try all the gods at any time if you need something new :D