How is your room “the most overlooked consideration when buying a piece of audio gear”? Because if your room is all lath and plaster walls, or super modern with large pane glass windows and concrete floors and walls, and is overly bright requiring gear that has significantly rolled off treble? Or because your room has shag carpeting with Elvis and tiger fabric wall hangings everywhere and acoustic tile ceilings that suck up treble? In those cases I see the room weighing on your purchasing considerations.
And while super important, purpose building a space for audio, or purchasing substantial room treatments for an existing space seems like a separate topic for a separate thread. When I think of purchasing gear, I think of stuff downstream of the electrical outlet and is available for purchase on Audiogon. Based on the OP’s original post, I think that is what they were asking about as well.
kn