They should be paid a ton. And in exchange, no stock trading, complete divestiture from any private businesses, and like a 10 year ban on employment in any private sector capacity remotely related to anything they legislated on or worked on while in office, to name a few sensible restrictions.
$175k seems like a pretty decent salary.
Your proposed role of diverstitute from private business would mean nobody with any business sense would run for office, which doesn't seem like a good thing.
This.
Many democracies have similar rules that prevent conflict of interests, but compensate you well.