Just checked (Nov. 25th, 2022 noon CST) the ore markets. Average High sell price is now:
Bauxite - 3.38
Hematite - 4.25
Quartz - 2.04
Coal - 7.15
Somewhere around 7 is a line whereby a tile won't pay for itself without including calibration bonus ore, talents, and/or adjacency bonuses.
(Math: 400l/hr * 24 * 7 = 67,200l/week. 500,000/67,200 = 7.4)
Yeah, I know that calibration bonuses, talents, and adjacency bonuses all count, but