I didn't mean to attack personally, if it felt that way, I apologize. I meant that your views to me are very contradicting than the masses and for no real good reason behind it.
Coming to your "efficiency" point, there's no benefit if you're paying the upfront cost higher. You're saving literally nothing in power costs if you pay higher cost initially buying it. It's like solar panels, you pay a huge amount to set them up and expect the returns decades later but this (GPU) is highly depreciating asset and will be outdated within 2 years. The higher cost you'll pay now won't be recoverable at all.
Again, it only makes sense to save money and go with higher end 30 series used cards and this is the perfect time for it since miners are offloading them in market. You'll save money upfront, you'll get a good VFM GPU and since you're not gonna use it 24x7 you don't need to worry too much about power bill as it's only in the ballpark of 50W or so. Those are my views and most of the known good reviewers say so as well but you're certainly entitled to your own.
Also, Nvidia never cuts prices below MSRP. On the higher end Nvidia has no competition and that's the reason the prices stay the way they are.