Untitled

<!doctype html>
<html lang="es">
<head>
<meta charset="utf-8" />
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css" />
</head>
<body>
<input id="datepicker" type="text">
<p class="dia"></p> <!--Se muestra el día seleccionado-->
<p class="precio"></p> <!--Se muestra el precio correspondiente al día-->

<script>
$(function() {
$('#datepicker').datepicker({
            dateFormat: "DD",  // Sólo obtener DD en lugar de " d MM, yy"
            onSelect: function (dateText, inst) {
             $("p.dia").html( "Día = " + dateText ); //  el día de la semana
             //hacemos la comparación día/precio
             if (dateText == "Monday" || dateText == "Tuesday" || dateText == "Wednesday" || dateText == "Thursday") {
               $("p.precio").html( "$3000" );
             }else if (dateText == "Friday" || dateText == "Saturday" || dateText == "Sunday") {
               $("p.precio").html( "$4000" );
             }
            }
        });
});
</script>
</body>
</html>