I bought mine at toysrus for around $30. It has a removable back so it grows with your child. It is very easy to put your child in and out of it, and easy to get the seat in and out of the car. Mine is a graco but my babysitter has a fisher price one and there really isnt a difference except the color.

I second the thumbs up on the Graco TurboBooster -- my nephew has had one since he was 3 and still uses the lower part (the back was removed when he was 4 or 5) now that he's 6 and still needs to be in a car seat -- the padding is easily removable for washing -- he has been able to get in and out and operate the seatbelt by himself since he was ~4, making it a really convenient seat