When are speakers considered Hi-Fi and not Mid-Fi???

i concur totally with retrocrownfan...

Most people had no experience and no idea about acoustic coupling of speakers with a specific room and the reverse...They then thougtht that price tags will spare them the need to experiment and learn basic acoustic....

My Mission Cyrus with a lesser high quality design were way better than my Tannoy dual gold ONLY because they were coupled to a dedicated room...Alas! when i learned basic  acoustic i had already sold my Tannoy...I can only dream of them in a room tailor made for them...

No speakers beat their room...

Sorry, but not a useful parsing. There are speakers under $1500 a pair that would embarrass most golden ear audiophiles in blind A/B test. HiFi vs MidFi is only about price and perceived brand value. Companies make ROI decisions based on volume of sales vs unit mark up. IAG in China has been a brilliant vertically integrated force with the market-changing products they engineer and produce under the venerable British brands they purchased.

I am not sure that i understand your question...

There is one thing in life exciting and interesting and it is NOT what you bought, but what will you do with the purchase...

The other thing exciting and interesting is being able to do the MOST with the less ....

Another thing interesting and exciting is KNOWING exactly why you will purchase something...And knowing you will never need MORE, not because your system will be a makeshift, but because it will be among top in the world by the ratio for the higher possible S.Q. for the less possible price...

Purchasing a 100,000 dollars speakers or amplifier or dac make no sense at all for me , why?

Because being there you will be in the obligation to buy a 50,000 bucks dac instead of a 10,000 one and the same for the amplifier....And they will not necessarily be the best.... The end results will be as in any uninformed purchase by faith in the price tags if not a mediocre system , a system which ca be rivalled at a way, way less price with basic knowledge or informed purchase...

With knowledge Hi-Fi can cost if not peanuts , not so much.... For me the top system i dream about is : under 15,000... And i know it will rival anything or it will not be too far behind...and i know exactly why this will be so...

The only thing costly in audio that impress me are room acoustic designed by pro...the price of any components passed a certain amounts is more snobism and ignorance most of the times, but not in all case for sure some people can afford the best and know how to purchase it...... Some TOP design are costly for a reason... But i can make something not far behind for less anyway...

When i begun my journey i was sad because i did not have any money to create my Hi-FI heaven... Now i know it was real luck , because i learned a lot... People with money most of the times dont learn instead they buy...

i dont feel frustration because i dont own a 400,000 bucks system, i dont need it at all ... The only case i will be envious is a dedicated acoustic room well designed ... This will cost at least 100, 000 bucks... And you dont need to put a 100,000 bucks amplifier and 100,000 bucks amplifier there AT ALL... I say all this not to criticize people who can afford that, why not? i say that for the people who cannot and feel frustrated... My message and recommendation is feel empowered by studying a bit and experimenting... This is way more rewarding than any purchase...

To answer your question :

For sure a 400,000 system IS HI-FI in principle, because at this price the design is at least good and better than most low cost systems ...But the room matter if not equally even more.... Then i need to experience this system in a room to decide if it is mediocre, good or TOP for the EARS...The room decide not the price tag of component in my experience...

The best system i listened to now is mine with 100 bucks headphone ... But think about that: do you think one of the best amplifier in the world in 1980 and one of the best headphone of all time and the flagship of AKG in 1978 is completely mediocre and without anything special ? You are wrong if you think so.... A stax Omega system in 1978 is always a top system... And my headphone rival them and beat them for the bass completely, i felt Baoch organ works with my body and feet... ... And the holography is to die for... Then ?

No one can make me envious because i know what i do with the components i pick...There are not the best in the absolute , only a fool can claim such a thing; but they are unbeatable in the ratio S.Q./ low price ...

Give me 12,000 dollars and i will upgrade and THEN  compete with anything almost...Nowadays anyway there is a revolution in DSP and dac, and most people dont even know about it... Then they pay MORE for LESS....

@Mahgister what if you are like tubebuffer and have a $400k system in your tool shed? Classy but not hifi?

If you like them, that’s all that matters 

An early definition of high fidelity may be found on pages 630-632 of the Radiotron Designers Handbook, 4th edition.  Too long to copy/paste here, but e copies of the book are out there.....it's a wonderful resource for those who enjoy tube gear.

Back in the day, a unified box consisting of a turntable, tuner and likely a couple of full range drivers was considered “hifi”. I’m sure many here recall the consoles of yesteryear 

Like everything else in this hobby, hifi is whatever works for you.