They get $743/week during the session. The session runs from January to April, with the exact end date varying based on the progress of legislation, governor vetos, etc. They are in regular session four days a week, not five, so your lodging math is off. They only get lodging if they stay in Montpelier - most commute and therefore do not get that.

Their pay is below the state average for salaries and is seasonal with no benefits. This is why it tends to be a bunch of fairly well-off people that can afford to be away from their regular jobs. Just this year a state rep lost her job because her employer was not willing/able to let her be away to serve.