WordPress Meta field repeater - ( taken from Easy Digital Download )

admin.js

jQuery(document).ready(function ($) {

  	var mux_repeater_configuation = {
			init: function() {
				this.add();
				this.remove();
			},
			add: function() {
				$('body').on('click', '.mux_ps_add_repeatable', function(e) {
					e.preventDefault();
					var button = $( this ),
						row = button.parent().parent().prev('tr'),
						clone = mux_slider_configuation.new_clone( row );

					clone.insertAfter( row );
				});
			},
			new_clone: function( row ) {
				
				var clone = row.clone(),
					id = parseInt( clone.attr('id') ) + 1;
				
				clone.attr('id', id);
				clone.find( 'td input' ).val( '' );
				clone.find( 'input' ).each(function() {
					var name = $( this ).attr( 'name' );
					name = name.replace( /\[(\d+)\]/, '[' + id + ']');
					$( this ).attr( 'name', name ).attr( 'id', name );
				});
				return clone;
			},
			remove: function() {
				$('body').on('click', '.mux_ps_remove_repeatable', function(e) {
					e.preventDefault();
					console.log('test');

					var row = $(this).parent().parent('tr'),
						count = row.parent().find('tr').length - 1;

					if ( count > 1 ) {
						row.fadeOut(400, function( element ) {
							$(this).remove();
						});
					}
				});
			}
		};
		mux_repeater_configuation.init();
});

meta.php

<table class="widefat" width="90%" cellpadding="0" cellpadding="0">
  <tr id="0">
    <td>
      <input type="text" name="prices[0][amount]" placeholder="<?php echo _e('Amount', 'mux_ps') ?>" style="width:100%;">
    </td>
    <td>
      <input type="text" name="prices[0][months]" placeholder="<?php echo _e('Months', 'mux_ps') ?>" style="width:100%;">
    </td>
    <td>
      <input type="text" name="prices[0][interest]" placeholder="<?php echo _e('Interest', 'mux_ps') ?>" style="width:100%;">
    </td>
    <td>
      <a class="mux_ps_remove_repeatable">×</a>
    </td>
  </tr>  
  <tr>
    <td class="submit" colspan="4">
      <a class="button-secondary mux_ps_add_repeatable"><?php _e( 'New', 'mux_ps' ) ?></a>
    </td>
  </tr>
</table>