Hoss is righter than you realise.
As a seller I come across this phenomenon quite regularly. You are walking on eggshells here buddy
My advice to you is not buy anything. Let the missus make the entire decision or you will pay for the life of the appliance. It may sound simplistic but just say,"get whatever you want" because whatever you spend hours researching it will eventually end up in the bin replaced by what she wanted anyway.
If she does not know what she wants; give her at least 10 options and make no recommendation WHATSOEVER
You are walking into an ambush, maintain eye contact, back away slowly, then run like hell.