How much valuation information survives when markets are incomplete and asset payoffs cannot be replicated? We develop a framework to quantify the arbitrage-determined component of non-replicable asset value and test it using commercial real estate as a laboratory. Out-of-sample tests show that traded-market risk premia materially improve valuation, especially when required returns change rapidly, notably during the Global Financial Crisis. The framework also identifies collateral valuation distortions and short-horizon price bubbles and extends naturally to embedded real options. Our findings show that arbitrage pricing remains economically informative under market incompleteness and applies broadly to non-replicable durable assets.