The level of markups has been well known for the last 50 years. What never stops surprising me is how many still happily pay them. The DIY crowd has long side-stepped this buy building their own loudspeakers and electronics. Even the good kit systems are a bargain.
The kit amplifiers from VTA perform just fine thank you at a fraction of the price of the big names. When you find them on the used market, theyʻre insanely cheap compared to new gear that performs no better.
People love to point to the Big Name brands and go on about how their engineers use proprietary magic dust. You can get equally good engineering from the better kit designs. The Joseph Audio Perspective 2, which retails for something around $14k or so today, is almost identical to the SEAS Thor kit, designed by Joe DʻAppolito himself, from Madisound at about $2700.
The Linkwitz Lab designs have long been hi-end audio reference grade. Even today, you could build the full LX521 system - loudspeaker enclosures, drivers, active crossover, amp channels and cabling, for well under $10,000. The LX521 compares just fine to loudspeakers in the $50k+ range. Tack on the major price tag for the amps buyers of the $50k+ systems use and itʻs not hard to drop more than $100k on an amp/loudspeaker combo no better than a DIY LX521.
Iʻm still running my Linkwitz Orions some 20 years now. Sill love ʻem. When you see them on the USED market, they can be had for very low prices.

