J.R.
Hi J.,
One thing I would not want to save money on is a carseat - if you buy 2nd hand, you don't know if the car was ever in an accident and if the seat was impacted negatively. Generally car seats are not supposed to be sold for safety reasons - they should come straight from the manufacturer, not anothers garage. A top of the line carseat is that usually for a reason - much reseach and development to warrant costing top of the line prices.
Baby's safety in the carseat is one thing to not put a $$ amount on.
Just my 2 cents :)
J.