Well, I charge $50 for a 10 inch two layer, 2 inch deep layers and $60 for a 10 inch, 2 layer each layer three inches deep.
This cake by Wilton sizes, party sizes serves 42.
Well, you are looking at about 2 1/2 cake recipes to do 3 inch pans and about 16 cups batter or just over three recipes to make 2, 2 inch layers. Plus all of the icing. Plus the time to do the bows, personally I don't like marshmallow fondant for these, but that is me.
I would likely charge about $80. And even at that, this works out to less than $2 a serving. If you made both bows for a total of $15, at your price of $45 or so, you are way low for the cake, in my opinion. Way less than a dollar a serving.
Never mind how nice she is or how nice you are, she isn't doing you a favour ordering, you are providing a service for a fee. Your Barbie cake would be worth a minimum of $60.
Haha, not trying to pick on you here, you are exactly lije the rest of us, embarassed about pricing.