AITA for re-gifting my boyfriend's Christmas present ($1300 laptop) to my sister?

I (23F) love my boyfriend (24M) and have been dating him for about two years. He has always been really supportive, and our relationship is great, so when it came time for Christmas, I wanted to get him something really special.

He has been complaining about his laptop for a while and has expressed the desire to upgrade to a newer model. I decided I would surprise him with a brand new laptop for Christmas.

I wanted to get him the best laptop I could, so for the weeks leading up to Christmas, when he'd complain about his laptop, I'd take these opportunities to casually ask him which laptop he liked, what he wanted in a new laptop, and so on. The main problem he had with his laptop was the speed. So, I thought it would be fitting to get him the same model that he had (MacBook Pro), just the latest version.

Now, I'm not a tech person. I don't know the first thing about RAM, SSD, etc. I just assumed a $1300 laptop would be more than enough for his needs. So I bought the laptop, without doing any more research into it.

Christmas day came and I gave my boyfriend the laptop. He was so excited, until he saw the specs. When he saw that the laptop had 8GB of RAM, he was really, really disappointed because he "couldn't get his work done on such a slow machine". He was adamant that he needed something with more RAM.

This turned into a full blown argument. I tried to explain to him that I had done my best and spent a lot of money on the laptop, so he should appreciate it, but he wasn't having it. He said he would rather return the laptop and get the one he wanted.

At this point, I was really hurt and upset. I had gone out of my way to get him a really nice present, and I felt like he didn't appreciate it at all. Yes, I could return it, and get him the one he wanted, but I had already spent a lot of money. The fact that he wasn't even willing to give it a chance made me really frustrated.

So long story short, I decided to re-gift the laptop to my sister (19F). She's a college student, and I know she could really use a laptop like this. I know it may sound selfish, but I didn't think it was fair that he didn't appreciate my gift, and I wanted to make sure the laptop went to someone that would actually appreciate it.

My boyfriend is, to put it bluntly, pissed. He "does not understand why I wouldn't just return it and get him the one he wanted" and "cannot believe I would do something so selfish when I know how much he needs a new laptop". I feel kind of bad, but at the same time, this wasn't cheap for me, and a little appreciation would have been nice.

AITA?