My DH is of the opinion that more expensive =better, esp when it comes to buying carseats. In DH's car we have got very expensive isofix seats. I need one for my car now and I would probably only be doing local driving.I have seen some carseats for about £30 which are suitable for 9months - 11 years. That just seems so cheap! Is it U to buy this or would I be compromising on safety?