This thread will immediately head into controversy, so I'll quickly convey my strategy.
I bought used Pangea cables -- the Pangea Audio AC-9SE MkII for my amps and the Pangea Audio AC-14SE MkII Power for my preamp, streamer, and DAC. All of these can be found used, especially if you're patient.
My reasoning: cables may or may not make a difference. I have a good but perhaps only moderately resolving system, so I don't want break the bank on cables nor do I want to be wondering if I am missing something. These cables, especially used, solved this question for me -- for now.
One caution: the AC-9 cables are kind of hard to wrestle with and you should consider how easy or hard they'll be to fit into your existing system setup.