Standards over both partners paying equally come from a perspective of them both being able to earn similar amounts. This gap isn't similar, and it doesn't sound like you have an option to just change jobs tomorrow and clear the gap.

Here are some likely scenarios he's paying for so much

(a) he just likes spending time with you and it isn't too much for his budget

(b) he's a gifter; people tend to express their love languages by going ham on what they like to receive. My husband and I had this a lot when we dated. I couldn't even afford food, so he bought me all sorts of gifts and bought me groceries and dinner and lunch and new goodies. I felt awful for a long time. I can look back now and see one thing very clearly: He was telling me he values me and wanted me to feel valuable, not bad about myself. In this scenario, he didn't mind my little budget gifts. That I was offering sincere love through them was worlds more valuable than high dollar items.

(c) he knows the gap is harder for you, and the idea of you stretching when it's not as much for him would kill his vibe, man.

(d) he values you. You ever get so tired of getting something cheap and cave to spend more on the higher quality option? He could likely find a closer partner who can cover their own gap more. He didn't. He found and picked you. It means you have a lot of positive qualities that mesh well with him, and the costs that feel unbelievable to you aren't that big to him because it's part of getting to be with someone he adores so much. Maybe look at this closer. Is there anything about you where he is just really excited? Shared hobbies, sense of humor, beliefs, goals, etc? I didn't get it with my husband because he had so many "closer" options in both income and proximity. Now that we've been together so long, I see it. There is nothing wrong with the other women he could've pursued, but they aren't compatible. I get him. He gets me. It's hard to find a match like that, so you fight as hard as you can for it and give it everything when you do. That's just how it is.

If you're offering him you're best, that's more than you can ask of most people. You're not taking advantage. Taking advantage is refusing to pay because you feel entitled. Love is accepting as much as you give, and love isn't a one-currency option. You take what your partner can offer, and they take what you can offer. You lift each other when one of you is down. That you worry about being fair with him is a big indicator it's not taking advantage, it's just the current state of your relationship. And it's fine. It's really fine.