Why is it not acceptable by our society (and wives) to spend big bucks on HiFi audio
I think this is a faulty assumption, I think spending a lot on HiFi is as socially acceptable as spending a lot of money on any other niche hobby or luxury.
However, if we assumed it really was less acceptable than spending on luxury cars or watches or boats or whatever, my reasoning would be this:
Everyone is familiar with stereo equipment. The headphones and speakers they might consider "really expensive" usually top out at $500. That's close to the ceiling for a single audio component in the mainstream world. In the "audiophile" world, $500 is considered entry-level for "actually" good sound.
Everybody has a rough idea of what an italian sports car costs, they're not surprised to find out it costs 5-10x what their own daily driver costs. But hifi is less mainstream, so there is a lot of sticker shock when someone hears what your system costs. They expect a really good system to cost maybe 2x what they consider "expensive", not 10x.
How much have you spent on this HiFi hobby over your life time?
I don't totally want to tally it up, but I think it's not nearly enough to buy even one Blade Meta, let alone a pair, and I've been buying stuff for 20 years. I probably recently increased the lifetime total by over 100% by snagging some LS60s.
Probably in part because I feel that telling people what I spent on audio would be awkward, I strive to buy secondhand whenever possible. That way no matter how much I spend, I can follow it up with "and, well, I got a really smokin' deal on them and I could probably sell them at a small profit if I needed to... it's about total cost of ownership, you see..."
Hell, even the WiiM Minis I have around were purchased from the "refurb" listing on eBay.
I think my only brand-new-paid-retail stuff in the whole house is a set of LCD-XCs (a gift) and a Topping DX5 Lite. (And a couple Fosi amps, I guess.)
All in all, the money I have tied up in stereo equipment is pretty close to what I spent on my car, which I bought with 75K miles on it.
How much do you spend on average an year?
In an average year maybe $200-500, but I also sell stuff secondhand.
Will you ever reach your end game and stop upgrading?
I may be close to that state. At some point you have to admit there's no compelling reason to upgrade unless something breaks. The only way I'd make major upgrades now would be if my financial situation took a big leap upward and I moved to a new, bigger house. So in other words, not likely.
How do you deal with your wife/gf/partner when it comes to HiFi spending?
Try to avoid talking about it and try not to object too strenuously when she wants to buy some $$$ handbag or clothing or whatever.