Geoff - The word "expensive" is relative to the rest of the system, the speakers/amp/preamp/sources. $10k on cables is not expensive if the rest of the system is worth $100k. However if the rest of the system is worth $12k, then $10k on cables is very expensive and would most likely not be the most efficient money spent in terms of improved sound quality per dollar.
In my system, I think its expensive and inefficient to spend $5k total on cables, which is where I'd be if I spend $1k on a single set of interconnects. I can get more SQ improvement for the same money elsewhere. But that's of course for my system, thus the need to be open-minded about different levels of cables, results will vary for different people. I also have a dedicated power line for example, that might change things dramatically in terms of how cables respond.
In my system, I think its expensive and inefficient to spend $5k total on cables, which is where I'd be if I spend $1k on a single set of interconnects. I can get more SQ improvement for the same money elsewhere. But that's of course for my system, thus the need to be open-minded about different levels of cables, results will vary for different people. I also have a dedicated power line for example, that might change things dramatically in terms of how cables respond.