Aw, thank you very much <3! We're so glad you like OL. The game is gonna be free for everybody with optional paid DLCs. Each DLC will cost around $3-$4 USD. Initially only three DLCs will be available to buy and it'll cost around $9 USD to get all three. Though, more will be released over time. Once all the planned DLCs are out it'll cost about $20 USD to get all of them.
We'll do our best to make the game worth the wait and DLCs worth the money ^^