You sound like my mother. She's a mindless impulsive consumer, just buy buy buy buy buy, because it's there, because it's shiny, because it's new, because I WANT!!! Then it gets promptly tossed aside and the process begins again.
She calls me mean and stingy for not buying impulsively, thinking before buying. I might pick something up, think about it, decide it's not worth it or I don't really need it and put it back. She thinks that's stingy and I'm 'counting pennies'.
Dd had plenty of toys when she was younger. But not piles and piles and piles. What the hell for? I've seen kids doing it, take it, open the package, toss aside, open another, toss aside. They get played with for 5 mins and never touched again, while mummy and daddy are bringing more.
I wouldn't have bought this doll either. She has plenty of dolls as per OP, never expressed interest in this particular doll, it's pricey. I definitely wouldn't have bought it and I'm not a man.