The Halfords £50 set covers a much larger range than 5-12. Unless you're using them hard every day, you don't really need to worry about getting a premium brand. If I were shopping, I'd probably be lazy and get whatever comes up first on google, which in this case is https://www.tester.co.uk/anton-aercs-extra-reach-combination-spanners-set-of-9
(No relation)
No 5mm, but then I've never been moved to use a wrench on anything smaller than M5 (8mm A/F) anyway. 5.5mm would be more useful than 6mm, since that's standard for M3, which is a mark against a set containing only whole numbers.
The Halfords £50 set covers a much larger range than 5-12. Unless you're using them hard every day, you don't really need to worry about getting a premium brand. If I were shopping, I'd probably be lazy and get whatever comes up first on google, which in this case is
https://www.tester.co.uk/anton-aercs-extra-reach-combination-spanners-set-of-9
(No relation)
No 5mm, but then I've never been moved to use a wrench on anything smaller than M5 (8mm A/F) anyway. 5.5mm would be more useful than 6mm, since that's standard for M3, which is a mark against a set containing only whole numbers.