I'd also suggest a britax. Roundabout is the most affordable & has lasted my kids RFing until 3 & FF probably until 5 or whenever a new baby comes & we need to pass the seat down. I have tall but average weight kids. We go from the Roundabout to the Frountier, which should fit my kids until at least 10.
I'm not sure there's actually anything on the market that will last until your child is too big for a carseat. Our laws here (CA) are 8 years & 80 pounds (but we will go til the limits of the seat) & most seats expire after 6 years. :/
ETA: Roundabouts can be found on Amazon for less than $200. I've haven't paid more than $150 for my britax seats (I have 3 so far).
Last edited by TPLmommy; 04-18-2012 at 06:32 PM.