Abstract Property prices, including, in particular, residential properties, vary across local markets. For example, according to the National Bank of Poland, in late 2018, the average unit price of an apartment on the secondary market stood at PLN 8,700 in Warsaw, 6,100 in Poznań, 4,800 in Szczecin, and 3,800 in Kielce and Zielona Góra. The level of prices on particular markets is affected by a variety of factors, primarily those of a social and economic nature. Earlier research work on the influence of such factors on the level of apartment prices was carried out on a random basis, and their results were also published in the Real Estate Management and Valuation journals (Kokot 2018). This article presents study results that help deepen and broaden such analyses, seeing as how the research work: – covers a period of 12 years (2006-2018), – proposes and then applies a city wealth synthetic measure (SMZM) in the analyses, – classifies cities according to the criterion of socio-economic factors and of average housing prices, – examines relationships within the groups of cities identified via classification. The obtained results indicate that it is justified to consider the impact of socio-economic factors on housing prices precisely in the context of their appropriate classification. Moreover, they may be an indicative tool of identifying so-called comparable or parallel real property markets.