The Demon's Bill: Maxwell's Demon Priced in the Frame's Own Currency

Maxwell's demon is thermodynamics' oldest unpriced assumption: a being that sorts molecules without discharging. The modern settlement — Landauer's principle — says the cost exists and names its currency: one bit of erased memory costs at least k_B T ln 2 of heat. This paper builds the bridge the frame has owed since it made counting a physical act: in this frame a count is not bookkeeping, it is an event with a grain (τ_cell) and a share (the sever's pair {200, 211}); if counting is physical here, the demon's bill must be met in the same currency, and it is. The Szilard gain and the Landauer cost cancel exactly (net 0.0 J at 300 K, computed, not asserted); discriminating the frame's own pair {200, 211} costs log₂(211/200) = 0.077243 bits, evaluated at 2.217630×10⁻²² J at 300 K; and a demon reading at the sever's own rate, one binary read per cell, faces an erasure power floor of 1.295107×10³ W per channel at room temperature. The demon is not forbidden. He is metered — and the meter is the frame's native instrument.