A good system with a bad power cable will sound better than a bad system with a good power cable. Same applies to all other cables. Yes, cables make a difference but they aren’t going to move the needle as much as fantastic primary components...not even close.
I actually completely disagree with this. Cables can make or break a good system.
I would rather do a $3000 system with excellent cables instead of a $10k system with mediocre cables.
The primary example I have is when I tested and compared two DACS. One was a $300 DAC and the other was a $2,000 DAC. With cheap cables, these DACs actually sounded pretty much the same. However, when I put in very high end and transparent cables, it become very apparent how inferior the $300 DAC was.
In your example, the sound quality difference between a $3k system and a $10k system is not enough to justify the $10k choice. The $3k system is already close enough. We are rapidly approaching the point of diminishing returns here.
Now if you were comparing a $500 system to a $3k system, then I would choose the $3k system with cheap cables every time.