This paper examines the biased price estimates and the relation between price estimates and return on art works. Using Korean auction price data from 1999 to 2022, we find that auctioneer presale price estimates are biased. However, it shows different pattern based on the sale price of art works. Price estimates are biased upward for low-priced art works but downward for high-priced art works. This result comes from the fact that the transaction volume of high-priced artworks are low, but that of low-priced art works are high. Thus, auctioneers tilt their estimates downward for expensive art works to increase the probability of transaction. On the other hand, auctioneers try to provide the high price estimates for inexpensive art works, as they can increase the winning price and in turn their commissions from the sale. Price estimates also affect the return on art works. The higher the price estimates, the higher the return. However, the greater uncertainty on price estimates lowers the return. Overall, our study suggest that art investors are likely to be influenced by price estimates.