My mom just came back from visiting my brother and SIL out of state. Since it's not a long distance she drove. They're getting rid of their baby gear and sent her home with lots of great items (snap and go stroller, swing, changing table, etc). One of the items they sent was their car seat. They've had three kids in close succession (the oldest is 4) so all three of their kids have used it. Also, I know they haven't been in any car accidents with the car seat. Would you use it? Also, if I don't care much for the cover/paddings could I change it? It's not that I'm picky, but like I said, they had 3 kids in close succession and despite her best efforts, my awesome SIL couldn't get it totally clean. Is there a safe way to change the cover? I know some people make them and sell them, but I'm uncomfortable with those...
Re: Hand me down car seat?
If it is not expired there is no reason not to. Although, after three kids I am sure it is pretty heavily worn.
IMO, I would just buy a new one.
Emily 8.8.08
Madeline 1.2.11
William 8.5.12
Since you know the seat's history I would have no qualms about using it. I would just confirm she never used anything stronger than dawn on the harness since stronger cleaners weaken the harness straps (although if she did you can still order new straps from the manufacturer for like $12 instead of buying a whole new seat).
As far as changing out the cover, that's fine. But, you need to buy a new one from the original manufacturer that is designed for the model you have. As long as it's purchased from whoever made the seat it's totally safe to use.
On that note, you could even just get new harness straps too. They can get yucky and can't/shouldn't be laundered.
You're right that the carseat is the most important safety item, but taking one that's been treated correctly, is not expired and is from someone you can trust isn't really scrimping IMO. I'll also say that my older two hated the infant bucket, so we only used it for a few months (7 for the older one, 2 for the younger) before switching to the convertible, so saving money there makes sense to me. The place I would go for exactly what i want is the convertible seat since you want the tallest shell you can get in order to keep the kid rear facing as long as possible. If I could I'd gladly by a foonf for #3 and not bat an eye at the $500 price tag since they could RF to at least 4 (my kids are tall with long torsoes out outgrow the RF radian before 3).
I say use it if its accident free and in good condition. Chances are your LO will only use it for a short while. Like a PP suggested, focus on getting the convertible carseat of your dreams (lol)!
If you absolutely have to get one that you love and is a different style/pattern then maybe you could save the hand me down for a second vehicle (like DH/grandparent/nanny/etc) and save the money not having to buy a second base!