定期价格下降

I was wondering if it is possible to add a drop down in the 'regular price' field in the product-data section of WooCommerce.

I want to create a drop down that has 3 options and prevents from the user typing in the regular price field (instead, he would pick one of the drop down options).

So basically 3 price options (in a drop down) within the 'regular price' field in the product-data section.

Any help would be appreciated.

I dont think you can directly modify that regular price field. One hack would be creating new custom field but with same name.

add_action( 'woocommerce_product_options_pricing', 'theme_slug_custom_product_field' );

function theme_slug_custom_product_field() {
  woocommerce_wp_select(array( 'id' => '_regular_price', 'label' => __( 'Regular Price', 'woocommerce' ) . ' (' . get_woocommerce_currency_symbol() . ')', 'data_type' => 'price', 'options' =>     array( '5'=>5, '10'=>10, '15'=>15 ) )
);
}   

This will add new field but with same name _regular_price. To hide default text field you could add some CSS in admin side.