New characters but...
I’m in that sort of situation (though I have a lot more than 8 characters). I have one character I don’t really want to play after all, and I bought a bag expansion slot on him. I didn’t want to delete him so I use him as a storage character right now.
I wish there was a way to transfer bag slots.
Bag slots should be an account wide unlock, especially in a game with so much emphasis on account-wide sharing and multiple characters. I know I would actually buy them then. I would buy the max amount of them.
I’m only here because sometimes I just like to watch things burn.
I don’t believe that particular feature is offered by CS.
If you do not want to purchase another character slot (they are on sale at present), you could always use the no-cost option of exchanging Gold for Gems.
Good luck.