That's an enormously high property tax bill for Chicagoland. I live in Oak Park, famously one of the highest-taxed areas in the county, in a relatively large house, and my taxes are not close to that (more than $10k less).

I don't doubt you or your friend, but their situation was unique.

I think he was in Oak Park. I drove by his place once. He has a pretty good size corner lot.

That said, he was often trying to show off, so who knows.