How Important Are System Cable Upgrades and Where to Start?

My limited experience indicates that the order of most to least important is:

Room Treatment: Room selection/ Audio furniture (vinyl playback)/ Equipment placement /absorbers/diffusers

Component upgrade

Component power supply

Power Source conditioning &/or dedicated circuit

Power Cable

Interconnect

Speaker cable

The exact order of the first five items likely vary a good bit depending on the room, starting components and quality of power.

What are your priorities?

Are your priorities based upon trial and error, or the logic of your thinking?