Inflation is also not what the guy with the sign is taking into account in his complaint. He’s at least 40 years older in that picture than he was when he bought his property if he’s getting social security. The real purchasing power of whatever he paid back then is much smaller than the same number of dollars is now.

$5000 in January 1985 would be the same as $15,055.50 now according to the inflation calculator on the Bureau of Labor Statistics