AITAH for giving my girlfriend a “dupe” of my sister’s gift for Christmas?

Hi everybody, I want to know if I fucked up or not. So I’m 19M, I have a little sister who’s 16 and my girlfriend of ~10 months is 19 as well. My sister’s birthday was in November, and my parents decided to splurge on her this year. She’s been wanting this jacket from this store called My Mum Made It, it’s the ruche tie jacket and it’s super pricey. Well my parents thought she’s been doing very well in her studies and extracurriculars this year, she’s aiming to get into a T20 college/bag a good scholarship at a T50 and she’s been working really hard so they surprised her with the jacket.

My girlfriend was over at my place that day and saw my sister’s gift, she mentioned offhand that it was very pretty. Later she brought it up again a few times in passing, it was obvious she liked it a lot, it felt as though she was dropping hints if you get what I mean. I decided to buy something like it for her for Christmas. The thing is, I’m in college and my parents are paying for my base tuition and dorms. But beyond that I don’t get an allowance, I work part time and use that money for books, groceries and personal things. So any gifts or stuff I buy for my girlfriend is out of my pocket. Unfortunately the original jacket is way out of my price range, I discussed it with my sister and she suggested buying a ‘dupe’ basically a similar jacket but from a different store and with a more reasonable price. I did just that and my girlfriend was very excited when she opened her present, she thanked me over and over again and kept saying I was so thoughtful and it was so beautiful.

Well my family hosted a new year’s eve party and obviously my girlfriend attended. At the party my sister was wearing the jacket, my girlfriend went over and spoke to her at some point in the night. My sister started looking uncomfortable halfway through the conversation. I guess my girlfriend sussed out that the jackets were from different stores. I think she went home and googled the price of hers because she flipped out on me yesterday. She called me and was ranting, she called me a cheapskate and said i had misled her, said how could I skimp out on a gift to her and some other very hurtful things. I was mostly caught off guard and she hung up on me before I could explain myself properly, and I have tried texting her, calling her etc but she’s ignoring me. Did I fuck up badly? If I could afford the original jacket I would have bought it without a second thought, but i genuinely could not, and I never lied to her saying it’s the original jacket or anything. I’m shocked at the 180 she pulled, she went from loving her gift to hating it because of the price? And I feel hurt by her comments, but now I’m thinking maybe I shouldn’t have touched this can of worms at all and got her something entirely different? I don’t know what to do tbh or how to address this.