AITA if I (F24) want to spend the same amount of money on gifts for my sister (F19)?

My sister (F19) wants to gift eachother holiday gifts. She showed me a pair of shoes that costs 110$. I (F24) asked her if she will buy me something also worth around 110$, and she said no. I asked her what her spending limit is. She asked me why she needs to tell me a limit, and I said so that I know how much I will also spend on her. She was confused and wanted me to spend more on her than she spends on me. It’s true I have a real job and she only has a cafe job, but she has a considerable amount saved up (15k+), as do I, and can definitely afford to spend the same amount. She told me she would like to only pay 50$ for my gifts, and I said that’s not fair really. She told me that she doesn’t want to fight and actually we should not swap gifts. Now she is upset with me.

For background info, our parents are/were paying for both our colleges, so we have no debt and we have spent no money of our own on college nor housing because they also house us. She has said she will have to pay for dental school by herself, which is why she is saving up, but im assuming not all of the paying will be by her, but also my parents will probably chip in.

She and I are only kind of close, not the closest sisters in the world. She is not there when I need her to be, and I am always there when she needs me. She always says no when I need a favor or some help. She has stated herself that she always says no and should really start saying yes, especially to simple, important stuff like bringing toilet paper if the paper is out and bringing medicine if the pain is too much to walk around. I have friends not very closer to me that are more dependable than she is to be honest. They are also much nicer.

I have spent a considerable amount on my friends and other family, for example buying my best friend a 700$ dog, giving my dad 5000$ for part of the roof repairs, and buying my cousin 200$+ shoes for his birthday every year. I buy things for people when I see something that makes me think of them because if they made me that happy, I want to give them something to show them how happy they made me, how kind they are, and how valuable of a friend/family member they’ve been.

I’d like to mention that she studied every day for 3 months, and passed a hard exam called the DAT. I gave her 250$ because I felt so happy for her, and she has different style than I do, so giving her money would be best so she can buy what she’d like. In contrast other than my birthday (spent less than 100$) (I spent 200$ for hers), she has bought me a 10$ item for my fish.

We have had this issue for a while now ever since she started using her own money to buy gifts for me. I just don’t know what to do anymore. I want to buy her stuff but I also wanted to be treated in return, if not by being nice, then at least with gifts.

TLDR: my sister wants me to buy her 110$ shoes for the holidays, and she does not want to spend the same amount on me for gifts. I did not like this, so she is upset.