are the typical Sram, Shimano, KMC, Connex/wipperman chains all similar enough to not give it much thought?
Are you asking about chain wear? https://bikerumor.com/...chain-lasts-longest/
Rank and price 2/28/19 google shopping
1 Connex 11xS $54-100
2 Campy Record $54-70
3 Connex 11xB $36-74
4 KMC x11sl gold $44-63
5 Shimano HG901 $33-50
6 Connex 11so $34-50
7 FSA N1 $18-29
8 Shimano HG701 $35-40
9 Shimano HG600 $30-40
10 KMC x11-93 $24-35
11 SRAM XX1 $39-57
12 SRAM 1110 $14-24
Basically you get what you pay for. If using just this metric plus price and assuming changing brands has no effect on watts or wear, cherry picking chains on sale seems to be the way to go.
Currently the FSA N1 seems to be quite the price performer.