Ethernet Cables

Recommended cables? 
If the builder wired your house or office with standard ethernet cable in the wall, will using Supra CAT 8 or ViaBlue 7 from the modem or router to your system make any difference?

Just asking...
OK, let's think this through...  What kind of ethernet cable is carrying the signal to the router and possibly to the internal switch in the house?  It's generally marginal semi-junk that is just sufficient to carry the signal.  Cheap copper.  

So what's the point in purchasing $500 ethernet cable?  Just use off-the-shelf cable that is rated above the speed of the connection.
Just saying.....
If the ethernet cable in your house negate any benefit from the Supra or ViaBlue cables, then all the people that assert that one cable or another makes the music sound better, are wrong. It also brings into question the whole aftermarket power cables industry.