Your greatest high end audio purchase!!!

Marantz 1060 Integrated Amp, Philips GA-212/B&O SP-12 and Large Advents. My college system. Had to have a TT with auto-stop. Put lots of miles on that system. Would own any of those pieces again.

Marantz 3250170DC/2110 Stack. Gorgeous to look at and to listen to. Plus the tuner had an oscilloscope! Should never have sold it.

JVC QL-7 Turntable. Better than any equivalent Technics, then or now. Should never have sold it.

My Apt Holman Preamp. Bought in 1981, rebuilt/upgraded in 2021. Will never sell it.

McIntosh MC-240 Amp. Customer trade-in for $100 credit on an Onkyo receiver. Retubed it kept it 20 years sold it for $1200 to buy my first home theater. Miss it.

Adcom 5400 (Nelson Pass design 100W/ch MOSFET) When all else fails, my 5400 comes to the rescue. Currently driving my in-wall subs in my theater. Might reunite it with my Apt for dedicated vinyl system.

VPI Super Prime Scout /JMW Memorial 10.5" Printed Arm/Hana SH. My retirement present to myself. A thing of beauty to look at and listen to, and nowhere near as cantankerous as VPI detractors would have you believe. Keeper.

Monitor Audio Silver 300 7G. Absurdly good speakers for the money. British refinement plus the dynamics of a JBL, all in a package that's intended to be placed closer to the rear walls than most, which is what my living room requires. 

There are lots of other pieces I've owned enjoyed, and sold or traded for various reasons, but these are the ones that that remain my 'greatest high end audio purchase(s)'

Great question and what fun to read everyone's comments! I owned a pair of original Snell Type-E's around 1981. I replaced the woofers a couple of times as the foam gave out. After Peter Snell passed on the company evolved away from my personal sound preference. My beloved Type E's wore out as well. Today I have one of the two spiritual descendants, the DeVore O/93's. (The other being the Audio Note AN-E's) In my room space the O/93's are wonderful. Paired with my Cary CAD 300SEI Integrated I drive them with 15 watts of SET goodness. Happy times.

Enjoying this post everyone. I don’t cycle gear much, tending to get gear that sounds good to me on a limited budget and listen to it for a long time. But sticking with the “greatest hi-end purchase”  question, it was buying a pair of Quad ESL 63s a few years ago. I joined AGon in order to buy them and got them from a great seller for a good price. Turning up the volume on these was a revelation. I never knew recorded music could sound that real. 
 

That purchase sent me down the electrostatic road to a pair of Sound Lab M1s and a pair of MC2500s bridged for 1000 watts. (The SLs are hungry.) All bought used. My wife, a singer, after listening for an afternoon, thanked me for buying them.  

I am going to cheat and answer this a little differently.  I am going to answer the question of "what was the most important audio purchase I ever made"?. 

The answer was a pair of Thiel 2.0 speakers in 1985.  Not that they were all that great but the options back then were pretty limited. What they did do was start me on the road to being a dedicated "follower of fashion", whoops I mean a dedicated follower of the Thiel brand.  I am now on my fifth and last generation of Thiel speakers,  the 3.7's, which are phenomenal speakers.  It is was great loss for the audio community the day Jim Thiel died.

I would say speakers I've had for 22 years would be qualify as a pretty good investment, and those would be a combination of the amazing 10" driver Innovative audio Cabinet speakers and Sub-table and the equally amazing Acoustic Research Phantom 8.3 low slung surround speakers. 

More recently would be the Oppo 205 of course, the best Blu-Ray player ever made even even today it can't be matched because of some of its features and even the DAC was state of the art six years ago (and still used in current components)

Last but not least is the glorious Audio Research MP1 100% analog multi-channel preamp.  This thing is built like a tank with a circuit board that looks like it was constructed by hand with individual daughter board per channel--and sounds equally sensational.   As long as I stay in the far superior sounding analog world, it's not going anywhere!

And finally for headphones, the drop-dead gorgeous titanium-infused Final Sudio Sonorous X cans that look is good as they sound. One of the most underrated products ever released in my opinion.