Choosing not to buy a car seat is not an option that a new parent can make unless they do not plan on driving their baby anywhere; however, you do get to decide between infant car seats and convertible car seats. A convertible baby car seat can be converted from a rear-facing car seat to a front-facing car seat, which makes it compatible for a newborn all the way up until the child is anywhere from 40 to 80 lbs. depending on the height of the child. You could also get a convertible 3-in-1 car seat, which can also be converted into a booster seat when your child outgrows the car seat altogether. There is a wide variety of convertible car seats to choose from on eBay for both boys and girls. The best part of purchasing this type of car seat is the fact that you do not have to rush to the store to buy another one because your child is not going to outgrow it.