Boyfriend vs Girlfriend

So I'm buying a Promise ring for my girlfriends valentines present, She has very small fingers so sizing has been a issue. I finally found 4 rings that fit her style and had her size. The first ring i found was an Amazon ring so i still chucked it in just cause.

All 4 rings have the same quality material, same quality stone, all similar price and similar styles.

I didn't tell her any of the prices or show what site any of the rings are from.

Out of the original 4 she ended up picking the Amazon ring. I laughed and told her it was a Amazon ring and she ended up switching to a different ring she liked.

Just to make it known they all cost similar amounts she just wants a the ring from a reputable store that only does jewelry not a store like amazon since its a important ring.

She says its my fault for putting a Amazon ring in the selection and not telling her, I'm saying its her fault for picking the Amazon ring.

So who is right? Should i have told her one of the rings was from Amazon so she wouldn't pick it or is it her fault for picking the amazon ring out of the 4 total options.

Just to clarify this is just a funny argument and we both want to know who is right since she wont admit im right and i dont think she is right at all.