Rogue Company will be a free to play title but it might require payment in order to access the currently running beta. Otherwise, you can hope for a Twitch drop.
Hi-Rez Studios are requiring payment if you are looking to get into Rogue Company closed beta. There are several packs that can be purchased on the respective store pages for PC, PS4, Xbox One and Nintendo Switch.
Each purchase will bring playable rogues and cosmetics, with the amount of each depending on which tier of access one purchases. Starter pack costs $14.99 and will grant access to two rogues and four cosmetic items, for example.
Standard pack costs twice as much and will bring eight playable rogues instead of two but the amount of unlocked cosmetic items will remain the same.
Ultimate pack will set you back as much as a AAA title, standing at $59.99 and unlocks eight rogues along with "a cache full of cosmetic items". It probably means more than four but the exact number is not specified. Furthermore, players who get this purchase will gain 1,500 Rogue Bucks for spending in the microtransaction store.
If you are not sure whether to put the money down for early access, you can go watch Rogue Company streamers on Twitch and hope for a drop. Just make sure you link Twitch and Rogue Company accounts in order to be eligible for such access.
Keep in mind that cross-progression is a thing in this game so linking the accounts across all the platforms you might be on could be a good idea.