AITA?

EDIT: I purchased the car seat myself

Our child needs a new car seat BADLY, I previously purchased her one by MYSELF but when my car got stolen they threw out her car seat so we had to go back to her infant car seat because I couldn’t afford a new one at that moment due to my job situation which was ok because she could still fit in it. Now it’s coming to a point where she can barely fit in it and I tell her dad to send half the money for it and he’s saying wait until next week because he doesn’t want to take out his savings but I’m telling him when you’re “saving” money, you don’t NOT take out because of your kids. Your kids are a necessity. He keeps saying how she doesn’t go anywhere and how she’ll only be in the car seat for 5 mins when I drop them off but I’m telling him anything can happen and she needs it today. I’m just frustrated because I don’t have that mindset, I will go broke behind my children especially behind their safety. I’ve been practically financially supporting them on my own and it’s built up so much resentment because I shouldn’t have to. He keeps promising he’ll do this and that and how he couldn’t wait to get a job to do this or that for them but he has the job and hasn’t brought a single piece of clothing. He’s a diaper/wipes kind of dad and I’m sick of it.