what is the difference between a £15 chain and a £30 chain
does it last twice as long , shift 2 times better
is half the weight , makes it easier to pedal ??

they are slightly lighter, more resistant to rust, because the £30 will be nickel coated. It is lighter, and will* shift slightly better.

*probably wont. 🙂

I read an article some time ago about sram that said the cheapest chains pc38 are not heat treated. the medium ones pc48 are heat treated. With the more expensive ones you are paying for bling plating that makes it look pretty but no more long lasting. So the pc48 was the sweet spot. I don't know how this information can be applied to the new sram model range or other manufacturers though.