%a{:href => link_page("price")}
%img{:onmouseout => "this.src='YOUR_START_IMAGE'", :onmouseover => "this.src='YOUR_IMAGE_'",
:onclick => "this.src='YOUR_IMAGE_AFTER_CLICK'", :src => "YOUR_START_IMAGE"}
Be sure to write the quote marks exactly as they are here, or it will not work.