Differences between High dollar rigs, hmm.
The Room is the critical thing, of course careful selection of gear matters. Bob Katz writes about this as does S.Olive at Harmon who seems to contemptuously sneer at the $250,000 rigs.
A customer buying a $35,000 Preamp gets very special treatment that the little DIY'r lives without.
At a certain price point, Wilson will send someone important to set-up your stuff. Figure .5 Mil to be safe.
The other side of the velvet rope isn't always a pleasant experience: Re-tubing for $10,000, up-grading to the nice Transparent Cable system for $100,000 are a couple of examples. If you've got loads of money and need to show-off your lofty position in society, buy one of Wilson's systems, some VTL, Clear Audio record player and a few vintage RR and/or vintage Sheffield Labs Vinyl.
Tony in Michigan
ps. Harmon does double blind testing of all this, the results are amazing. For now, the $20,000 JBL M2 is about as good as loudspeakers can get.