I’d be cautious about choosing one dataset first. Mixed-use sales can be hard to compare because two similarly priced buildings may have very different tenant arrangements, condition, or income potential. A first-purchase checklist might be more useful: financing assumptions, legal questions...
What buyer structure are you considering: personal ownership or a company? Also, are all buyers Polish residents, and does the property include land with any classification that could affect ownership permissions? I wouldn’t assume an answer based only on the Warsaw address or the “small...