The CE Schmidt brand of insulated overalls and coveralls was on sale yesterday at a Tractor Supply store in CT

The link shows retail pricing. I don't recall the sale prices.
http://tinyurl.com/2hm3xp

I have a pair of these
http://www.ridegear.com/rg/item/F-27298/Firstgear/HT-OverPants-2-0.html
They're a might bulky, but very warm. A pair of heavy duty suspenders made them more user friendly to me. My only complaint is they aren't designed for use without the liner due to the way the padding is attached.