Lvl 31 atm. Yes I've spent money but didn't need to. I bought the battle pass, the cheaper one, then I upgraded to the more expensive. Also bought some very cheap packs.
It's annoying that everything is character bound and not account bound. This is where the real money sink is.
I don't see myself buying consumables to increase my drops. I think the whole gameplay in Diablo is about grinding for gear, not buying it outright. When you do that the game loses its purpose.
The game is pretty good.