The whole cost of Hardware vs. cost of software is not a valid comparison, I think.
The cost of software is relatively fixed. Sure, you can spend hundreds on that really low serial number MoFi pressing of your favorite piece of music. But for the most part the software is going to average somewhere in the neighborhood of $15 per edition. (give or take) This means that in order to make the "ratio" anything meaningful we'd have to have literally tens of thousands of individual cds/lps. And, obviously, some of us do. My buddy, at last count, had over 30k lps.
The problem with this is that there is simply not enough time in the day/week/month/year to actually listen to a collection that big.
So it begs the question, whats the point of spending tens of thousands on material that never gets listened to?
My own music collection is probably somewhere in the neighborhood of 400 pieces. I only buy stuff that I know I will listen to often. And I listen the crap out of that stuff, easily 3-4 hours per day.
So for me, if there is any meaningful ratio it's the one comparing cost of system to total hours actually using the system. But even that has it's problems. You'd probably have to somehow figure out how to include the "cost" of the time spent. Ie. If you make $X per hour, how does time spent away from earning impact the ratio?
But in truth, due to the way equipment is priced these days, there is no way to determine ANY meaningful cost ratio. The correlation of cost and performance is woefully low. If it weren't, the 6/7 figure systems would ALWAYS unanimously be regarded as the best. And they simply are not, both subjectively and objectively.
Which leaves us with the inevitable (and huge) part of the equation that takes into account the thrill in SEEKING the ultimate sound. And this has very little to do with cost.
By way of comparison.......
I love sailing and at various times I've owned a few different boats. A small, one man, dingy is probably affordable to most people. And I have one hanging in my garage right now. In the past I've spent significantly more money to get larger and more impressive boats.
The foundational motivation is being out there on the water, feeling the wind and waves and harnessing the power of the sail. And a bigger boat with three times the sail area as the little thing hanging in my garage amplifies that thrill.
Most friends, who have never sailed, don't see the thrill in it. All they see is all the work that goes into upkeep, docking, rigging, etc. etc. They for damn sure don't understand why I would want a more expensive boat.
Sure, I love my little sailfish. But I enjoy the catamaran more! And if I had the $$$ for a 12meter yacht, you can bet your last dollar I'd have one.
Sure, part of it is the thrill of exclusivity. The thrill of owning bigger and more expensive stuff than the next guy. But most of the thrill is in the pursuit of what that money brings with it.
This thrill exists in countless forms and genre.
Just like audio. There is a real and valid enjoyment in laying down some big bucks on a new peice of equipment and then going through your listening collection and have it take on a different character than previously experienced.
In this sense, the guy with a superbly whacked "ratio" has every bit the same size collection of music as the guy with tens of thousands of CDs.