Yes, that price is outstanding, Unless there's something drastically wrong with it, I would buy. Your weight will not be an issue at all, and you will get used to handling with a child seat on the back pretty quickly, but definitely get comfortable without it first. Have you looked into trailers? I remember really liking them when my boys were younger.
My wife is exactly where you are, and just getting back on the bike has been such a benefit. Ride, ride, ride!
Andy