xx1 chains only £30 anyway, why bodge it?
10 speed chains (tried KMC and Shimano) work perfectly as do Shimano 11 speed. However, the XX1 is the lightest chain I’ve tried (out of KMC X-10 SL, Dura Ace, XX1) and is similar money so no real reason to not use the XX1 unless you have a ton of 10 speed chains lying around that you stocked up on
N/W ring on the existing chainset is what most people seem to be doing and makes sense unless you are in the market for cranks anyway. No real way to get around the high cost of the cassette/ shifter/ mech unfortunately besides lots of shopping around on ze German sites. X0 saves a bit but other than that not many tricks I don’t think. The freehub cost also seems to vary a lot between wheels so that may make it more/ less expensive relative to other people.