Most of my gear was bought second hand over the years. I had a pretty good dealer connection, so I was able to get trade-ins and such. A lot of unusual stuff came and went. As far as buying new? I could never relate to the 'spend as much for your preamp as a German car' mentality.
New, the single largest all at once outlay for me was a pair of Klipsch LaScala II I purchased five years ago. I think at that time they were 8K for the pair. A polarizing loudspeaker for sure, but each time I read something telling me I should not like them, I listen and realize it was a great purchase. The latest AK models are too expensive, IMO. Then, a Benchmark AHB2/DAC3HGC combo I bought to go with the LaScala loudspeakers--those were about 5K for the set.
Next was probably a 'package deal' I bought new--> Acoustat TNT-200 amp; TNP preamp; and 2+2 electostatic loudspeakers. As an 'all in one system' I most likely received some sort of discount from the dealer, but I don't remember. This was in the early '80s. I thought it was a good combo. If I still had it all I'd probably be happy. As long as it was working. Parts for that brand are probably unobtanium. Interestingly, that dealer who sold me all of that is still in business, but now does 'home automation', dedicated movie rooms--stuff like that. High end gear is nowhere to be found on his sales sheet.
Last on the 'new' list, for a 'single' purchase was probably a ReVox B77, or maybe it was the Teac X-1000. But probably the ReVox was more expensive. I'm happy not to have those anymore. But they were pretty cool to look at, and did what they were supposed to do--until they didn't.