What is the optimal time for a firm to buy inventory to sell in a product market in which the selling price and demand are random and their forecasts improve with time? What is the value of order timing flexibility to the firm? What lead times would a supplier see? To answer these questions, we develop a continuous time inventory model where demand and price are realized at the horizon date T, and the stocking decision can be made at any time in the interval [0,T] given progressively more accurate forecasts of price and demand and a time dependent purchasing cost. We show that the optimal timing of inventory ordering decision follows a simple threshold policy in the price variable with a possible option of non-purchasing, and is independent of the demand. Given this policy structure, we evaluate the benefits of timing flexibility using the best pre-committed order timing policy as the benchmark. We find that the time flexible ordering policy is particularly valuable in the high price volatility or low margin environments. Higher price volatility leads to a greater postponement in the purchasing decisions. In addition, decreasing profit margins lead to a higher lead time variability.