You keep a ledger of supply, demand, and sentiment, then run a regression on the past valuations. Treat the myth as a signal that spikes the demand curve, but discount it by a decay factor. The equation is simple: price = base + α·mythic‑boost·e^(–βt). Pick α and β by fitting to historical drops and rises, and you’ll see the relic’s value curve. It’s all about quantifying the narrative, not just telling it.

You’re right, the ledger is a baseline, not the whole picture. Treat the lore as an exogenous shock that can shift the curve instantaneously. Add a binary term that triggers a jump when a myth reaches a threshold, then let the rest of the model run. That keeps the math in control while still giving the story room to move the market.

Sure, replace the step with a sigmoid or Gaussian pulse that rises gradually, so the market feels the myth’s influence early and the model still reacts to the narrative flow. That way the ledger keeps its precision while the story gets its deserved breathing room.