Cheap/expensive or expensive/cheap?

blueorion,

"...(as well as my non-audiophile friends) heard a noticeable difference on better ICs followed by speaker cables----not as much on the conditioner and power cords."

This sentence of yours should be at least half of the answer applicable to you on the question you asked in original post.

For some, the question is a non-question. Better electronics/speakers will always outdo worse electronic/speakers, no matter what functionally adequate cable (conducting and with good joints) you put there.

zzzzzzzzzzzzz

Are we talking two $10K systems in comparison or not? Not specified, as the expensive cables are left nebulous. 
Systems comparable, i.e. MSRP or not? (i.e. $3K used vs. $10K new, or not?)
Floor standing speaker vs. bookshelf?
Analogue vs. digital?
Class D, older AB, etc? 
Mixed loom of cables vs. set of cables? 

These questions reveal the problem with the question; it is so general that it does not offer much benefit in answering it. Everyone has a purportedly great answer, and they all have marginal value. 

The only proper answer is that direct comparison would tell, despite the tendency of most to attempt to predict the outcome. 

OP - everyone's response likely has some merit, hence your question isn't going to result in a definitive answer. Like Mr. Schroeder says above, reframe the question more narrowly/precisely and you will get more useful answers.

My experience has been variable, but in my system/room, I come down on the side of spending more on gear rather than cables when your per unit cost is under 5K. My system is 25K total, about 10% of that is in cables and power conditioner. That 10% has become like a guideline for me (and that includes tweaks like isolation pads)... but as mentioned, there are more experienced industry folk in the more rarefied end of the hifi universe who might say 25% or more should be allocated to cables/conditioner/tweaks. 

Auxinput-a 10k system isn’t reaching the point of diminishing returns? Are you talking about $10k worth of cables? I hope so because a $10k system can still be classified as a starter system or maybe getting into The midfi range, depending on what components you are talking about. A good dac with a good power cable and ic’s alone are $10k or higher. A good turntable/arm/cartridge/phono preamp with cables start around $10k, on and on.