When buyers can't see quality, good sellers exit and the market can unravel — Akerlof's model of adverse selection.
See why hidden quality (information asymmetry) drives out good products and can collapse a market — the mechanism behind scams and “too good to be true” offers.
Leave the optimistic opening offer and watch several rounds play out.
Before you act, predict what will happen. Did the quality you actually got hold up, or did it slide as the price fell? Then do it — did your prediction match what happened?
The lemons spiral, round by round
When buyers can't see quality, the price they'll pay and the quality they get chase each other down to the equilibrium.