Is High End Cable Really Worth It and What Brand


Hello. My system is almost complete. I'm just waiting for the Dynaudio Center to arrive and my McIntosh AV system will be up and running. The dealer wants me to change out my speaker cable (which I paid a lot for), claiming I will get much better performance out of the dynaudio speakers. The cable I bought (from another dealer) was expensive, but not by the standards of what I'm being told I need. Any advice here would be most appreciated. Is it worth $500.00 of cable? I don't want to have things just for the concept. I will pay if the results are real. I just don't know. Thanks for your advice.
jsdk
A reasonable priced cable that sounds very good in my system is Canare 4S11 "Star Quad".  I ordered mine from Blue Jeans Cable, if you do so make sure the terminations you ask for are compatible with your amp and speakers.  A Mc I used needed small forks, not spades.
As you are working with a dealer, he should be very glad to let you try the wire he claims is better for your system and you can judge for yourself.  That is the only way to tell.  And I do agree that wire is very system-dependent.  With one set of speakers I own, Blue Jeans 10 gauge sounded as good as some expensive cables I own.  With another speaker, the BJ made the piano sound shrill and harsh, but the other cable was worlds better. But after your system is together, I would try it with the wire you own and then borrow the wire your dealer recommends.  
Interesting jump-start to an 18-year old thread - reads like it was just yesterday.  The more things change......