AITAH For wanting a graduation dress?

I’m a graduating high school senior, and about a month ago I approached my step-mom about if we could go shopping for a dress for graduation. And she said yes, that’s something we could do. I asked my step-mom again today if we would still be able to go shopping. She told me she wasn’t sure anymore, and told me my dad said, “Why would you buy something we can’t afford, that no one will see, when she already has so many clothes.” Now, my issue is not at all about whether or not I can get the dress, I have been in financial struggle before. I have been homeless, I understand the difference between a need, and a want. They act like I can’t handle a no, or that I don’t understand financial priority.

Which I do, just today I had a job interview where they hired me on the spot. And I am so excited to start being more independent and paying for my own things, (ie: Gas, Car Insurance, Groceries, Wants, Etc.) I was even planning on taking my whole family out to dinner with my first paycheck, because I want to pay everything back to them, even though that’s not even nearly what they’ve done for me, it’s a start.

I’m not sure if I’m being entitled. Currently, I have everything I need and I’m in a very comfortable position, by no means do I think I need a dress, I just want one.

My main issue overall is their attitude towards me graduating. For months I told them I needed to order my gown, they never did. My grandma had to do it. She also bought my prom dress, which I know is also a luxury. My boyfriend is having a grad party, just a simple gathering with some grill and barbecue, and because my parents are doing nothing, his mom made it our party instead. I had to ask if we could go out for dinner afterwards because if I didn’t say anything we would have done nothing. (I know this too is a luxury) They have just expressed zero excitement towards one of the most important occasions of my life so far. I just wanna know they actually care :(

Please let me know what you guys think I’m open to criticism