Relative component value to overall SQ.

Personally, I'd rather buy lps than to sit back trying to think of a descent thread...…..

Amen, slaw. CD's too ;-) . Even the radio, if you happen to have a good station nearby.

@inna "This thread was clearly started by non-audiophile."

I think you are correct. The more time I spend on Audiogon the less I think that I am an audiophile. But I'm okay with that.

@inna "The question makes little sense in real world and one never leaves the source and the recordings out."

Agreed. That's why I very clearly stated in the original post:

"Let’s assume that the CDP, DAC, streamer, server or TT are delivering an optimal signal of an optimal recording to the system."

@slaw "Personally, I'd rather buy lps than to sit back trying to think of a descent thread...….."

And yet, you see seem to find enough time between buying LPs to make negative comments that bring no useful content to a thread. Good for you. At least you've got your priorities in order.

Not only is this what I would tell a newbie. This is what I would do myself if I have to start over and did not have $30,000 to $50,000 to play with... (I am assuming not a lot of money to spend here. If you DO have $50,000.. then forget what I am writing!)
As far as money goes, a newbie should be spending zero on ’room treatments’. First off you have no idea what to listen for on placing them. And thus IMO you are 90% likely to place them wrong. Or you are placing them where some online guru who also has no idea since they are not there in your room, but they have the chutzpah, and you don’t.
As for cables.. zero on power cords. the stuff came with power cords. use those. Buy bulk power cord for the speaker cable. Folks used it for fifty year before high end. Still works just fine save a bundle. Buy cheap IC, Blue Jeans, Kimber PBJ, etc.. I would tell a newbie to spend a lot on the speakers. used would be best. Not more than 40% to 50%. there IS a danger you buy speaker which are too good, and show the badness of your other cheap stuff! Then on the source. 20% to 30%
Plenty of cheap decent used amplifiers and preamps at a low price.Brand is not so important. just a well known one. All the malarkey about particular brands is malarkey for a newbie. older is fine. particularly find really old used ones where the previous owner replaced the caps in the past few years, usually a good deal. 20% max..