On 2010-04-09 auctions on the National Bank of Poland has been finished and issue's prices was established for coins commemorating the Lesser Horseshoe Bat.

Coin with the denomination 20 zł:
 - Reserve gross price: 104 pln
 - Max gross price: 120 pln
 - Selling price (price of issue): 120 pln
 - The number of coins to sell: 98.000 pcs
 - Total emission: 100.000 pcs
 - Date of issue: 2010-04-21

2010-04-19 is a date of issue coin with the denomination 2 zł and total mintage of 1.700.000 pieces.