I think it’s impossible to get 100k, very high end system sound with 5k. But you can get maybe 75-85% of the way there. That last 15% will cost you exponentially more as you near 100%.
I do think however, that you can get 98% of 100k system sound Q for around 25k. For example, a preowned Hegel 590/600, and preowned Perlisten S7T or Boressen X6 towers. IMO you’d need to spend a lot more to get significantly better sound.
A Borresen, Schweikert, etc might kill a 5k or 10k rig, but, i have heard rigs in that price range, which sounded better to me than others in the high end...Mbls, Sonuses, etc.
Sure, the Sonuses or D’Agostinos look real pretty (audio jewelry and prestige pricing), but, i wouldn’t be shocked if someone preferred a rig in some lower range (5k or 10k) purely for sonic reasons over the latter. Not everything in the high end is worth its salt sonically, if the consideration of audio jewelry is discarded, imo/ime.