pmpro-change-price-by-date.php

<?php   // do not copy this line.
/**
 * This recipe will change the price for a membership by the date
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

function pmpro_checkout_sale_price( $level ) {
	
	$month = date( 'n', current_time( 'timestamp' ) );
	if ( $month == 12 ) {
		//december
		if ( $level->id == 2 )  {
			$level->initial_payment = number_format( $level->initial_payment - 2, 2 );
		}
	}

	return $level;

}
add_filter( 'pmpro_checkout_level', 'pmpro_checkout_sale_price' );

/* change price by month text */

function nicer_pmpro_level_cost_text($text, $level)
{
global $pmpro_pages;
$month = date( 'n', current_time( 'timestamp' ) );
if ( is_page( $pmpro_pages['levels']) && ( $month == 12 ) ) {

	if ( $level->id == 2 ) {
		$text = "Your what 2 text Here";
	}
	
}

	return $text;
}
add_filter("pmpro_level_cost_text", "nicer_pmpro_level_cost_text", 15, 2);