With 2 under 2 I'd like to think I'm an expert, LOL. BRUs/TRUs will be clearancing last years models soon and  if you sign up for their Emails they will send you coupons plus activly using your rewards card helps improve the frequency of mail flyers. They should also be doing their Trade in Event, bring in old baby gear(they recycle it) and they will give you 25% off something new. A few years ago I was able to score a 500.00 crib and 150.00 organic matteress for under $250.00 by combining sales, rewards and applying for their credit card.I would think if you are purchasing a car seat for your car and it would not be being used daily, besides safety look at weight limits and shoulder strap ajustments, the higher the weight limt and more strap ajustments the longer it will last. When I was shopping I read a book called Baby Bargians, it gave detailed (the most through I've ever seen)info on car seat Safety, comfort and price they also have a  web site w/ Forum moderators that are trained in car seat safety and installation.Last I know Costco got a good rating for value and safety but it is bare bones style for my infant seats I chose Graco and Evenflo for my convertables… Good luck.