edit

src/Api.php

@@ -424,7 +424,7 @@ class Api
                     $city_price = $city['price'];
                 }
                 if ($city_price < 0) {
-                    if ($level) {
+                    if ($level && $level['city_price']) {
                         $city_price = $level['city_price'];
                     } else {
                         $city_price = 0;
@@ -457,7 +457,7 @@ class Api
                     */
                 }
                 if ($county_price < 0) {
-                    if ($level) {
+                    if ($level && $level['county_price']) {
                         $county_price = $level['county_price'];
                     } else {
                         $county_price = 0;
@@ -481,7 +481,7 @@ class Api
                     }
                 }
                 if ($town_price < 0) {
-                    if ($level) {
+                    if ($level && $level['town_price']) {
                         $town_price = $level['town_price'];
                     } else {
                         $town_price = 0;