diff --git a/uncloud_pay/models.py b/uncloud_pay/models.py
index fd9eab8..f4d4c52 100644
--- a/uncloud_pay/models.py
+++ b/uncloud_pay/models.py
@@ -794,24 +794,31 @@ class SampleOneTimeProduct(Product):
 
     default_recurring_period = RecurringPeriod.ONE_TIME
 
+    ot_price = models.IntegerField(default=5)
+
     @property
     def one_time_price(self):
-        return 5
+        return self.ot_price
 
 class SampleRecurringProduct(Product):
     default_recurring_period = RecurringPeriod.PER_30D
 
+    rc_price = models.IntegerField(default=10)
+
     @property
     def recurring_price(self):
-        return 10
+        return self.rc_price
 
 class SampleRecurringProductOneTimeFee(Product):
     default_recurring_period = RecurringPeriod.PER_30D
 
+    ot_price = models.IntegerField(default=5)
+    rc_price = models.IntegerField(default=10)
+
     @property
     def one_time_price(self):
-        return 5
+        return self.ot_price
 
     @property
     def recurring_price(self):
-        return 1
+        return self.rc_price
diff --git a/uncloud_pay/tests.py b/uncloud_pay/tests.py
index 9aa86ef..69af3cc 100644
--- a/uncloud_pay/tests.py
+++ b/uncloud_pay/tests.py
@@ -327,6 +327,38 @@ class BillTestCase(TestCase):
 
         self.assertEqual(len(bills), 2)
 
+
+class ModifyProductTestCase(TestCase):
+    def setUp(self):
+        self.user = get_user_model().objects.create(
+            username='random_user',
+            email='jane.random@domain.tld')
+
+        self.ba = BillingAddress.objects.create(
+            owner=self.user,
+            organization = 'Test org',
+            street="unknown",
+            city="unknown",
+            postal_code="somewhere else",
+            active=False)
+
+    def test_user_no_address(self):
+        """
+        Raise an error, when there is no address
+        """
+
+
+        self.assertRaises(uncloud_pay.models.BillingAddress.DoesNotExist,
+                          BillingAddress.get_address_for,
+                          self.user)
+
+    def test_user_only_inactive_address(self):
+        """
+        Raise an error, when there is no active address
+        """
+
+
+
 # class NotABillingTC(TestCase):
 # #class BillingTestCase(TestCase):
 #     def setUp(self):