I just blow 46k gacha seeds and got 2 4* and 1 HP ampy.
With that I used 20 FG on yolo rolls and got 2 shit 3*, 1 dupe waifu Paulia and 1 new Bride Camelia. I don't know anything about her but okay. It's nice.

Well. I saved 30 FG and I'm pretty sure it's easier to get 6* through premium gacha than 4* through normal gacha.