Money-Making

Overview
The game is best thought of as a means to read a story. To that end, until you are approaching the high level (all stats at or near cap and so forth), the best sources of Echos are the content you're seeing. The only exception to this rule is that when you see content related to A box of secrets, play that content as that leads to the "gold standard" Echo grind.

The Grinds
Your best methods for echo grinding are the following:

Fate-locked

 * Fate-locked expeditions (7 Fate for 5.3 epa [under correct conditions])
 * Fate-locked Soul Trade (1.74 epa)

Regular Grinds
Aside from drawing the correct card to convert later, the following can be done only with skill-checks.
 * Collections of Curiosities via the Tomb Colonies connection card (1.78 epa, 62.5e/35a)
 * Investigations in the university and cashing in the Flit (~1.78 epa, easily locked out of)
 * Big Rat Grind (1.77 epa, 80.9e/45.5a, easily locked out of, but can be brought back w/ Fate)
 * Boxfuls of Intrigue with the correct choices (1.64 epa, 23e/14a)
 * A furious and incoherent drunken rat (4.14 epa [with a mood & max shadowy], spends SiC, incl. actions getting SiC ~.93 epa, not including rare success)

Luck-based Grinds
The following have a range in pay-outs and should only be considered in extremely large (1000 tries) batches for an overall epa.


 * Polythreme with a 5 card lodings (2.1 epa on a perfect run, averages much lower)
 * Tale of the Fidgeting Writer (1.99 epa, might be higher)

Historical
These grinds worked for some people at points in the games past but currently are not believed to be profitable.


 * Fate-locked selling your soul (used to be 2.3 epa, but was nerfed dramatically, current epa unknown)
 * Hunter's Keep Searing Enigma rare success (Used to be 1.85 epa, but has since been decreased)
 * Drinking Bottled Oblivion

Reference
These aren't grinds, but are here to show you how many echoes you're earning. * this might be higher
 * A Thieves' Cache (1.48 epa |3 progress| or 1.41 epa |2 progress|, supplies via Connected: Docks and the Tankard)
 * A Shrine of the Deep Blue Heaven (1.34 epa |3 progress| or 1.27 epa |2 progress|, supplies via Connected: Docks and the Tankard)
 * Beastly Breeding: Somnolent Hyaena(1.3~1.22 epa, depending on breeding method)
 * Thefts of a Particular Character (1.26 epa [with a Gang of Hoodlums])
 * Unfinished Business: Shake down your agent (1.52 epa, this is liable to be so wrong, the ranges on the wikia page mustn't be complete)
 * Unfinished Business: Eavesdropping, Ambush a few couriers for old times' sake*, The prince of..., Doing the decent thing., A sure bet, Wade into the Ring Fights (1.2 epa)
 * Unfinished Business: any other option that gives out rare successes (1.15 epa)
 * Unfinished Business: the other options (1.1 epa)
 * Unfinished Business: The study of antiquities, A lovely thought, An admirer among the clergy, A literary sort of fist-fight, Contracts and legs (1 epa)
 * Unfinished Business: The anatomy of a secret, Mischief and brass (~including Church loss) (.95 epa)

Unknown EPA

 * Unfinished Business: Encourage the honest folk of Spite to give you 'gifts'
 * Robbing various locales
 * Duelling the Black Ribbon
 * Acquiring Exhibits for the Labyrinth of Tigers
 * Velocipede Squad
 * Foreign Office

Cards
Only listed are cards that provide higher than 1.5 epa. Rare Frequency Cards: Grinding scraps to trade in with one of the Relickers for one of the Tier 8 (1562.5e) items only works if you limit yourself to 3 scrap or higher actions.
 * The Listing Tower: a Half-Abandoned Mansion (5e, but with a very difficult Dangerous challenge)
 * The Neath's Mysteries (4e, only at your lodgings [2.5e with a different option])
 * A Visit (4e with a base stat at 200, except for Persuasive & the Sardonic Music Hall Singer)
 * All fear the Overgoat! (2.5e or 3.2epa [25e/8a])
 * Call in favours in the Flit (28.8e, [3.2epa, 28.8e/9a] or 20 scraps [8.6e of scraps])
 * The High Castle: What Occurs in a Rooftop Shack (3e, if you go with the Repentant Forger)
 * The Paronomastic Newshound (2.5e)
 * The mechanics of progress (average modified Watchful pence [in Cryptic Clues])
 * Promenade with the Celebrated Artist's Model (2.5e + some Making Waves)
 * Ask the Sardonic Music-Hall Singer to help you (2.5e, going with the Repentant Forger and His Amused Lordship)
 * One's public (2.3e, but with a very difficult Persuasive challenge)
 * Wolfstack in the fog -> Crying his wares (2.2e from buying a Stained Red Velvet Gown at the Bazaar and selling to the ragman, only in Wolfstack docks)
 * The Lofty Tower: the Potential of Premises at the Bazaar (2e + 4 scraps [3.7e incl. scraps])
 * More Larks with the Young Stags (1.8e)
 * A day out in your Clay Sedan Chair (1.8e)
 * What will you do with your Grubby Kitten? (1.7e)
 * Once upon a time in a carriage (1.65e)
 * A disgraceful spectacle (12.5e)
 * The mournful rubbery instrument (3e, only in Spite)
 * A commotion above! (2.9/2.5/2.2e, only in your lodgings)
 * A flash of white (2.5e, only in Ladybones Road)
 * A Raggedy Creature (2e, only in Veilgarden)

The Nadir
Then there's also these Nadir cards Without question the best echoes per action in the game is this. It's repeatable, but it's only available so long as you haven't opened the Cave yet. It also costs 50 fate. But hey! 312.5epa. You'll have a goat in 37.5 actions and Hesperidean Cider within a week.
 * The End of Battles (62.5e)
 * An Unlikely Garden (62.5e, perhaps not with a second chance until you get a success)
 * Old Bones (with A Daughter in the Shadows, ~12.5e [kinda])
 * Woods in winter (with a Tattoo [from the Feast of the Exceptional Rose], 1cp of dramatic tension)