Infant car seats?

Maggie

Is it better to get an infant car seat, then buy a bigger one when they outgrow it? Or is it better to get a convertible car seat that the baby can use as an infant up to 8-9 years?

We’re having twins, and those convertible car seats look so heavy with all the layers and padding. But I also don’t want to have to buy a new car seats every year or two.