Except that the minimum for 80+ Bronze is 85% at 50% load, not 80%. That Bronze rated Corsair CX600 has been tested to run 350-400W at a bit over 87% efficiency, so for ~370W DC draw (what mine run at when set to 400MHz), that's 425W AC for the CX600@87% and 407W AC per Ant for the RM1000@91%. That's a savings of 18W per unit, or 36W together. For me at ~$0.15/kWh, or a savings of a little under $4 per month for two Ants.
I'd probably still go with the RM1000 just because it looks like a really nice supply and it's not group regulated, but it's a long payoff for that vs two CX600's if the price difference is $100.
rm1000 will be better psu in long term for future miners or will be better suited for use in a pc. you could sell them easier i think if you had to sell some of your psu's. i think rm1000 is the best choice for miner psu.
I never said is wasn't, I just disputed how you went about that. I just have a bit of a pet peeve with people using math to justify the wrong conclusions, and your numbers were wrong since you started with the extremely incorrect idea that the CX600 was 80% efficient. Almost nothing made these days is only 80% efficient from 50-80% load, unless you're talking about the generic grey ones that will come in a $40 case.
I'd disagree that selling the RM1000 for close to full price ($200) would be easier, even to other miners. The number of PC users who are running three GTX780s and an OC'd processor and actually need 1000W is vanishingly small. Getting $50 for a CX600 is likely going to be a lot easier.
The biggest benefit to a single larger PSU is that they tend to be a single massive 12V rail with the minor rails run off that using DC/DC. Some of the smaller ones like the CX600 are group regulated, so they can have issues with crossloads like miners put on them. They're also more flexible; the CX600 could easily become limiting if you want to move up and now power a board that draws 700W. That, and it only uses one plug and the footprint is smaller, so you use less rack space.
Regardless, from strictly business point of view, it's going to take a long time to make up the extra you pay moving from something like a CX600 to an RM1000 based solely on power costs. The gap from silver to gold or gold to platinum is ever more unjustifiable.