Free for a limited time. 

store.epicgames.com

"The original shooter-looter returns, packing bazillions of guns and an all-new mayhem-fueled adventure! Blast through new worlds and enemies as one of four brand new Vault Hunters – the ultimate treasure-seeking badasses of the Borderlands, each with deep skill trees, abilities and customization. Play solo or join with friends to take on insane enemies, score loads of loot and save your home from the most ruthless cult leaders in the galaxy."

Websites for SHiFT codes

Borderlandsshiftcodes (reddit.com)

SHiFT Codes (@dgSHiFTCodes) / Twitter