var testx=document.getElementById("priceMatrix");
testx.options[testx.selectedIndex].text=toAdd+"|"+cupSize;

var myText = toAdd+"|"+cupSize;
    $('#priceMatrix').filter(function () { return $(this).html() == myText; }).prop('selected', true)
    var alertText = $("#priceMatrix option:selected").val();
    alert(alertText);