If they start processing ore at 2.45 oz/t, then the calcs will be as follows:
Let's see- ((2.45 oz/t x $1200) x .85)-$50 = $2449 net/t. The .85 accounts for the 15% (.15) royalties to GHDC. And remember, you have to subtract $50 costs for each ton, not for each ounce. At 2.45 tons/oz, that's $20.41/oz costs.
So net $715/t x 50 t/day = $122450/day x 30 days = $3,673,500/mo x 12 = $44,082,000/yr.
Subtract $1M for lease payments, and you have a net of $43M/year. That's AFTER processing costs, after lease payments, after the 15% royalty. That's more than their debts- meaning they could be debt free in less than a year after startup if they want, though some of the money will be used for share buyback, mill improvements, reopening the mines, etc. And they own their own mill on their own property next to the mines.
Ramp up to 100 tpd yields 2 x $44M = $88M/yr - $1M = ~$87M/yr AFTER costs.
200 tpd = $175M/year
300 tpd = $263M/year
400 tpd = $352M/year
Producing gold at $20/oz? That is insane!