How did a US Senator earning $174,000 a year save enough money for three homes

I assume the new Bernie Sanders $600,000 "camp" doesn't have a dirt floor. But it does have 500 feet of shoreline on Lake Champlain. This is his third home. I'm very certain that 99% of his supporters either have one modest home or are renters. And from the news articles, he didn't have to borrow for the purchase. So, it begs the question, how did a US Senator earning $174,000 a year save enough money after supporting a home in Burlington and a town house in DC to pay cash for the Champlain home? Do his supporters see any hypocrisy here? Apparently, running for President can increase your net worth. Interesting.