/**
 * Customize Sell Content Price
 * Set a custom price for post content based on post type or
 * taxonomy relationships.
 * @mycred
 * @version 1.0
 */
add_filter( 'mycred_get_content_price', 'mycred_pro_content_price_by_type', 10, 4 );
function mycred_pro_content_price_by_type( $price, $post_id, $point_type, $user_id ) {

	$post_type = get_post_type( $post_id );

	// Pages always cost 5 points
	if ( $post_type == 'page' )
		return 5;

	// Posts in the category "premium plus" costs 10 while all other posts cost 15
	if ( $post_type == 'post' ) {

		$terms = wp_get_object_terms( $post_id, 'category', array( 'fields' => 'slugs' ) );
		if ( ! empty( $terms ) && in_array( 'premium-plus', $terms ) )
			return 10;

		return 15;

	}

	// Returns default
	return $price;

}