Gas Prices not moving much September 28, 2017 News Tweet Share LinkedIn Email gas prices have settled a bit in the wake of Hurricane Harvey along with other factors. in marshalltown, the price for a gallon of self-serve regular gasoline is $2.45 a gallon. Grinnell has the lowest price at $2.20 per gallon. Leave a ReplyYour email address will not be published.CommentYou may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong> Name * Email * Website Δ