DD is zeroing in on the limit of her infant car seat that we use in DH's car so I'm looking into getting a convertable but, I don't want to spend $$$ considering she in rarely in that car.

When we go out we use my car and when DH is off and wants to take her somewhere, we swith cars for the room. (he has a small Sentra, I have a SUV Highlander)

We have a Britax Marathon in the Highlander and it's ok. Looking for recos on safe yet affordable car seats. I'd like to keep it under $150 if I can help it.