In my opinion, high end, medium and low end are determined by performance and quality, not price. Of course many of the best sounding components are expensive but there are exceptions and the exceptions are brought about by matching the right pieces.
Some of the worst sounding systems are the VERY expensive ones that are severely mismatched. With the power and resolution to show every detail, a mismatch only serves to make the listener unhappy and even uncomfortable.
So answering your question by filling out components that "fit" the list, is difficult. An inexpensive DAC might sound really good with a computer based system, creating a super value sound, placing it low end in cost and mid to high end in sound.
Same with speakers. A used pair of Vandersteen 2Ce might be found for $650.00 or less, making them mid line cost but delivering reasonably high end performance.
Power related products are all over the place. Some very expensive conditioning equipment damages the sound on my system and some inexpensive ones improve sound.
Cable is a little bit easier. Low end would be door bell wire or zip cord. Works and sounds OK, with everything being "lossy" as opposed to showing much in the way of flaws.
As you move up the cable chain, all of the premium brands contribute their personality but the price does not always assure an equal amount of performance increase.
When you get to source, the best value is probably a $99.00 CD player. It works, sounds OK and no money spent. You can spend 30K on a CD but unless EVERYTHING else in the system is top notch, you'll wonder why it costs so much.
Same true for analog sources (turntable, arm and cartridge) and preamps and phono amps.
Sorry if this sounds like a cop out, but audio is like cooking. Better ingredients can make a great recipe better but is no guarantee a bad cook will serve a perfect meal.