Do cheap but v good quality car seats exist?

[Murtette]

We're thinking it would be easier if the grandparents could have a car seat to keep at theirs for each of our DC (one just going into 13kg+ car seat & one going into 18kg+ car seat) for the odd occasion when they need to do emergency pick up from nursery or similar. In all occasions, they won't be going more than a couple of miles and these journeys will always be in 30mph zones. Do I need to spend £100+ on each car seat and go for a maxi cosi/Britax which is what we have in each of our cars? It seems a lot to spend for a back up - although I'd obviously never forgive myself if there was an accident and the DC were harmed when, for the sake of a few quid, they would have been fine had they been in a better quality car seat.
Thanks

I am fortunate that we have a large family and extra car seats are usually the ones passed from a relative (so obviously we know they have not been involved in accidents.....) for example, the stage 1 seat in Granny's car ame fom an older cousin and one if the boosters in Granny's ar came from another cousin.

Our Britax Prince was £50 from Kiddicare

We are the first in our family (both immediate and extended) to have DC and the age gap between our first DC and that of friends is less than 2 years so hand-me-downs are few and far between which makes child raising rather expense!

The Britax eclipse is on sale in halfords(hope link works as im on my phone). for £70 at the moment. Its a good seat. They also have the Britax first class for under £100 as well if gps have long belt buckles this seat has an alternate routing that can be used to prevent buckle crunch.

As for booster i would say look at the britax adventure this is a good quality seat and if you look about can usual be picked up for around £40.

Kiddy care have the britax hi-liner (same as adventure) for £30 here.