There are LOTS of affordable products that perform right on the edge of the most expensive esoteric units. By affordable, I mean what most working adults are willing to pay if the sound is worth the price. That means a used Sony table radio for some. A used Yamaha receiver and a pair of Elac or Warfdales for others. It may mean a lot more. Careful used shopping can of course pay off.
If I were to define the minimum of what I consider true high end sound excluding prestige or hearing damage level playback, I might suggest:
Audiolab 6000 integrated, Sonas Faber Luminna IIs, SMSL Do300 DAC, Monoprice sub. Some kind of streamer, Wiim or what ever that thing is. Cables form Monoprice, Amazon etc. I venture that is 99.9% of what is possible. That last .1% is a real bugger. Real, but hard.
That is still several thousand dollars which is a lot of real money to most of us, but it is actually high fidelity. Is the IOTA or similar as smooth sounding as the Autiolab? Or spend a bit more for a Hegel? You hit the diminishing returns real fast. Mojo or Aries DAC worth it? How far short is a JDS Atom amp from the most exotic headphones amp? Not much. Is a $9000 preamp any better sounding than $109? I would not bet on it. Prettier. Nicer feel. More inputs. Maybe your choice of masking distortion. But not more neutral. I do sort of miss the masking of my Nakamichi preamp with it's tone controls. Nostalgia maybe.
Unfortunately prestige, looks, and ego drive the high end market. Usually you do get great sound. Some of it real, much of it placebo. Both making you happy. Hopefully you get reliability. Want a lifetime amp? Buy a Mac or Bryston. Billet aluminum cases don't sound any better. Braid over a power cord does not improve imaging. VU meters are eye candy only. No amount of user end electronics can make the source better. They can only degrade it. Some degradation is considered to be "musical". Some is not. Some is a tradeoff we are willing to make not to get a different defect. Personal preference.
Yea, I would put a set of $50,000 speakers on a RadioShack receiver and the next best dollar spent would probably be better speakers, it there actually are any.