Sorry couldn't help myself in the end
Love a bit of shopping...
Joie Tilt, Rearfacing to 4 years, Forward facing to 4 years, £70 Kiddicare/Halfords
Joie Steadi, RF to 4 years, FF to 4 years, £100 Mothercare/Halfords/Kiddicare/Argos (Looks like more side impact protection + better recline)
Joie Stages, RF to 4 years, FF to 7 years, £120 Kiddicare/Halfords
Britax First Class Plus, RF to 2 years, FF to 4 years, £90 Amazon
Also:
Joie Every Stage, RF to 4 years, FF to 12 years, £160 Halfords/John Lewis
I know it's a bit higher but it goes for the extra stage. Though by that point you might be happy using a booster without backrest anyway, so could be a false economy.
These are the best prices I've found, and I wouldn't trust any other brand at those price points. There are a lot of cheap seats on the market, and most of them are awful, a few are good. Joie and Britax are definitely trustworthy brands.