FWIW, Sainsburys currently do a largish set of ring/crescent spanners for £4.99 - at least at Whitechapel. Quality isn't all that special but not as ghastly as one might fear - the 15mm lives in my bag and has coped fine thus far. Rings are slightly harder to mash up than crescents even if the metal isn't hardened in any case.
FWIW, Sainsburys currently do a largish set of ring/crescent spanners for £4.99 - at least at Whitechapel. Quality isn't all that special but not as ghastly as one might fear - the 15mm lives in my bag and has coped fine thus far. Rings are slightly harder to mash up than crescents even if the metal isn't hardened in any case.