May seem like a stupid question but can I somehow get BL3 for free on Steam if I have it on Epic? I’m aware you can transfer save files so was wondering.
No. Not sure if the Steam sale is still on, but that’s probably your best bet.
(Also, edited your title to match your actual question.)
You can add it to Steam as a ‘non steam game’ if you prefer to launch from there, but that lacks the full social functionality of a native Steam game, I believe.
It’s on sale until March 20th I believe.
You have to buy it on Steam, but as stated you get trading cards, steam achievements, and watching SHiF go down every time you try to do co-op play with your friends.