I am relatively new to Fallen London having arrived about 6 weeks ago. My highest stat is a 70, the rest are in their 50s, and I just started running expeditions in the Forgotten Quarter.
That established, here is my question. When discussing the "worth" of an object, do people usually mean the price to buy, or the price to sell? In other words, is 100 Whispered Secrets worth 1 Echo, or 2?
Perhaps it doesn’t matter which I choose as long as I stay consistent.
By default the worth of an item is determined by what you can get for it, either by selling it at the Bazaar, or by using some action that gives you more than what you’d get there. Examples: Using Strong-Backed Labour for Expedition Supplies, using Strong-Backed Labour to emancipate Clay Men, and trading Collections of Curiosites to the Tomb-Colonists.
But if your options are to use item X (which you have) or to buy item Y, then the worth of item X is the buying price if item Y (assuming that they are equally good for whatever you need them for). A free Scuttering Squad from the advent calender could be valued at 500 Echoes if you were otherwise going to buy one, or it could be valued at 10 Echoes if the most profitable thing you can do with it is to sell it at the Bazaar. It all depends, really.
As long as something can be farmed, you generally don’t have to buy, only to sell. So I’d use the selling price. Still, there are some equipment that is hard (but possible) to farm, if you ever get one, consider yourself lucky and count them by the buying price.