Biggest "bang for the buck" audio gear you have owned(in your history)?

From above:

"Love to see the large Advent's mentioned.  Mr. Kloss was a pretty smart guy--I mean, he invented the acoustic suspension speaker...where would be be today without that?"

The acoustic suspension speaker was invented by Edgar Vilchur.   

1. Energy 22 Reference Connoisseur loudspeakers that retailed for $2400 USD in 1989 in Teakwood veneer, that I scored for $500 in factory cartons. Still have but replaced them only 14 months ago. Amazing 2-way floorstanding monitors.

2. Full-blown mod of Energy 22’s in 2018 by Agon member, Grannyring. Amazing improvement from top shelf caps, resistors, wires, custom stolen air-core inductors and binding posts.

3. Synergistic Purple fuse in Innuos Zenith Mk 3.

4. Audiocrast Spring pods for under speakers

5. KEF KC62 subwoofer added to Lyngdorf 3400- Audiovector Arrete’-Innuos rig. So amazing. A second one will be installed.

6. Perfect Path Technologies PPT Omega E Mats.
7. Audiovector Freedom Grounding cable.

SonographTT  with Sumiko arm and Talisman S cartridge. $550 1983 Still own TT and arm.

B&K ST 140 with B&K Pro10  $850 1985 sold both in 2011 for $425 (the pair)

BEL 1001 MK5  $1200 2011 Sold it for the same price in 2021.

Magnepan MMG $600 and now the Magnepan LRS + ($1100) If you have enough current and power in your amp. These speakers, decades apart are killer!!!! For the money.

Kingko KA-101 Pro integrated amplifier. Never selling mine. Hard to find as others apparently feel the same way. For both high efficiency speakers and especially headphones.

Kingko KA-101 Pro Tube Integrated Amplifier

I also like the iFi audio Aurora all-in-one system.

iFi audio Aurora