The info I have seen (sorry no reference) is that All SRAM chains last the same if cleaned and lubed well. You wont get significantly longer life from a high end chain. It may be easier to care for with reust-free sideplates.
With cheaper chains you can use 2 of them, one kept in cleaning solvent , and switch them every few weeks. This means that you dont have to take your bike out of action to keep the chain clean.