/* Tribe, hide cost for recurring instances other than the first */

hide_cost_recurring.php

<?php

/* Tribe, hide cost for recurring instances other than the first */
function tribe_hide_cost_for_recurring_instances ( $cost, $post_id, $with_currency_symbol ) {

	$event = tribe_events_get_event( $post_id );

	if ( $event->post_parent > 0 ) {
		$cost = '';
	}

	return $cost;
}


add_filter( 'tribe_get_cost', 'tribe_hide_cost_for_recurring_instances', 10, 3 );