Final answer:
The seller's expected revenue from the second price auction is the second-highest valuation among the independent valuations of three buyers, but a specific revenue amount cannot be determined without knowing the actual valuations.
Step-by-step explanation:
The question concerns the expected revenue from a second price (Vickrey) auction, which is a specific type of auction where the highest bidder wins, but pays the second-highest bid. In a Vickrey auction, it is a Nash Equilibrium for all bidders to bid their true valuation of the item because they pay the second-highest bid if they win.
Since we have three buyers with equal probability of having high, medium, or low valuations, and these valuations are independently distributed, the seller's expected revenue is less straightforward to calculate without additional information on the actual values of high, medium, and low. If buyers play the Nash Equilibrium, each will bid their true valuation. The revenue for the seller will be the second-highest of the three valuations, but without specific values provided, we cannot determine an exact monetary amount for the revenue.
Understanding imperfect information in markets is also relevant here because it can affect the willingness of buyers to participate in the auction if they can't assess the true quality of the painting, potentially leading to lower bids.