Cost comparison with Penstock's Land Agency.
From Fallen London Wiki
At Penstock's: 1250 Brilliant Souls, or 625 Echoes.
Here:
100 Muscaria Brandy, or 250 Echoes;
plus 500 Brilliant Souls, or 250 Echoes;
plus one Brass Ring, or 12.5 Echoes;
minus(because you are gaining, rather than losing, these items) one Uncanny Incunabulum(12.5E) and 5 Aeolian Screams(12.5E) for a grand total of 487.5 Echoes, so 137.5E cheaper than Penstock's.
