Ed,
I'm not sure all those numbers are what you think. For example, you're taking the 5.1 oz and assuming it is the production for the day. But if you look, it's simply the total Au + Ag per ton (107g + 50g)/(31g/oz) = 5.1 oz. So 5.1oz is weight per ton of concentrate, not weight per day. We'd have to know the amount of concentrate produced per day to calculate the total weight of Au and Ag. And, in the longstanding tradition of SFMI, we're not given the numbers we need.
But we can make a reasonable guess at production rates. In the 5/17 PR, they said they processed 3005 tons of ore in 3 months, which is about 33 tpd. I think this is low, since I think the mill alterations and construction probably lowered the throughput. So let's say 40 tpd.
For 5/2, we get (.4226g/t Au x $1500/31g) + (20.72g/t Ag x $33/31g) = $20.44 + $22.06 = $42.50/t. For 40 tons, that's $1680. Since milling costs are ~$50/t, $42.50/t is not quite breakeven.
For the other days, we get $47.34, $137.53, and $109.27 per ton, or $1893.60, $5500, and $4370.80 per day. Once again, one breakeven day, but two days of nice profit. Totals for a year based on each of the 4 days would be $605k, 681k, 1.98M, and 1.57M, for an average of $1.2M, about half what you calculated. That's a bit puzzling, since it would mean they are producing about half a ton of concentrate a day. In the 5/17 PR, they said they produced 2.61 tons of concentrate in 3 months, so either they have ramped up production (a lot, ~17x), or have optimized the mill process to get more concentrate out.
If they can improve the grade and process so they average or exceed the two best days (~$5k/d), that's $1.8M/yr. Mill costs should be ~$700k/yr (40t x $50/t x 360d). I would guess those numbers will actually improve quite a bit with the in house lab and better weather so they can transport better ore.
