Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: I feel like an absolute retard because this is the lamest post I've ever made in my life, but my girlfriend has been hinting to me that she wants a new phone for her very first Christmas (her Iphone 5 is 6 years old and fucked).

Just to preface, she's by no means gold digger, we always pay for one and other when we go out for a meal or buy something. We are both stingy people, and she has made me more conscious of my spending. 

Anyway, I'm happy to buy her a new phone, but she's been hinting at one of the newer model IPhones (IPhone 8, XR, w/e) which I think is a waste of money since, from my research, they aren't that different in specifications from the IPhone 6, which is far cheaper in comparison. I don't like the idea of disappointing her on Christmas but I'm not spending 800 - 1k AUD on some overvalued phone, so I implicitly said to her that the IPhone 6 is better bang for buck and than any higher model and she argued against me, saying that it was only 1 model after her phone, blah blah. 

Honestly the technical details of the argument are irrelevant, I just want to know how I should handle this behaviour. Am I being a stingy asshole? Am I an asshole for not wanting to buy a product I don't believe is worth it for HER? I was considering working part time for like 10 shifts just to pay for the phone XD but am I just spoiling her? Honestly if she said "Oh a 6 would be fucken sweeeeet" I would have done that for her but now she has pissed me off.

Help me assholes

not wanting to buy my GF an IPhone higher than the IPhone 6 for Christmas