To remove custom option pricing from the dropdown, you need to add below small piece of code to “select.pthml” file

Location of “select.pthml” file:

appdesignfrontendThemesyourthemeMagento_Catalogtemplatesproductviewoptionstypeselect.phtml

<script>
  require([
    'jquery',
    'domReady!'
], function($) {
    $(document).ready(function() {
        $('select.product-custom-option').change(function() {
            $('option').each(function() {
                var selectedOption = $(this).text();
                if (selectedOption.indexOf('+') > -1) {
                    selectedOption = selectedOption.substring(0, selectedOption.indexOf('+'));
                    $(this).text(selectedOption);
                } else if (selectedOption.indexOf('-') > -1) {
                    selectedOption = selectedOption.substring(0, selectedOption.indexOf('-'));
                    $(this).text(selectedOption);
                }
            });
        });
    });
});
</script>