What would be a good "back up" carseat?

Ashnmike528

My mom mentioned wanting to get a car seat for Ava for her car, because it's a pain to move our Britax from my car to hers.  Plus when I'm in the hospital with DD2, my mom and DH are going to be passing Ava back and forth, and it would just make life a little easier. We are not in the position to buy another Britax, so I'm looking for something not as pricey, but still very safe.

Any suggestions?