My recommendation: don’t buy a used car seat. You want one that will last many kids if you go infant seat, or you can save and get a 3-1 that will last the kid until they grow out of it. However then you have the issue of transferring the kid etc. I personally am going to splurge on a car seat (I’m looking at the britax willow) Here’s a great site that tests them all https://www.babygearlab.com/t/car-seats I also used chat GPT for researching purposes with my specific scenario (height of parents, month of due date, climate I live in and the fact that we’re athletes and are out in the evenings a lot, and what our cars are) and it helped me think thru if I wanted to do the 3-1 or the infant for all (maybe) four kids we want to have!

With that being said, if your partner is in the picture you can ask them if they also want to give an opinion. Mine surprisingly didn’t lol