Many banks publish quarterly reports on the subject. They give the average asking/list price of apartments and houses and the actual average price achieved, based on notarial deeds for the period. There are sources on the internet where you can find the same information. Use Google translate to help you search and read the reports.
bankier.pl/wiadomosc/Akty-notarialne-nie-klamia-Mieszkania-srednio-nawet-o-30-proc-drozsze-niz-przed-pandemia-8621998.html
Great. I don't mind paying an annual membership or something similar. I've taken a look on the land registry portal but this just gives me the mortgage amounts. There is nothing I can see that has a sold price. Anyone getting a mortgage may put a bug deposit down or may get extra lending for home improvements. I'd like to know exact amounts, for particular properties, as opposed to the average for an area. Many thanks
Here is a paid service that gives the information you want. I would suggest that you learn how to use Google Translate to search for information in Poland. You will never get the info you need by searching or asking in English. I used the following search term to find the service:
"jak sprawdzić kwotę, za jaką sprzedano nieruchomość"
urban.one/blog/skad-wziac-ceny-transakcyjne-nieruchomosci-sprawdz-poradnik-u1/#:~:text=Mo%C5%BCna%20si%C4%99gn%C4%85%C4%87%20r%C3%B3wnie%C5%BC%20do%20publicznych,czyli%20autorskie%20wyceny%20rzeczoznawc%C3%B3w%20maj%C4%85tkowych.
