You need to remember that in Poland the final amount of duty depands on an Officer of a Customs Office.
You can check duty rates in Isztar - Customs Service of the Republic of Poland System ISZTAR - Tariff Information
You can find basic information about importing goods to Poland - Ministry of finance basic information
Here you ou can find basic information about Economic Operators' Registration and Identification - EORI
UPS restrictions - List of prohibited articles