Right now get the Britax Frontier 90 Booster Car Seat for $195.07 on Amazon. Super Saver Shipping is free.
This is a really good price for this seat! It is a harnessed booster meaning that you can either use it as a 5 point harnessed seat or a high back booster.
I have two of the older version as back up seats for my 4 and 6 year olds and they are great seats and are very easy to install in the various vehicles we have used them in. My son was able to stay harnessed in it until he was six, at which point I felt he was mature enough to use the seat in booster mode (though the seat could have harnessed him for a good while longer).
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