diff --git a/app/Models/User.php b/app/Models/User.php
index 41e124e..92d3129 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -87,11 +87,11 @@ public function getBirthdayFromIdCard(string|null $id_card = null): Carbon
         }
 
         $bir = substr($id_card, 6, 8);
-        $year = (int) substr($bir, 0, 4);
-        $month = (int) substr($bir, 4, 2);
-        $day = (int) substr($bir, 6, 2);
+        $year = (int)substr($bir, 0, 4);
+        $month = (int)substr($bir, 4, 2);
+        $day = (int)substr($bir, 6, 2);
 
-        return Carbon::parse($year.'-'.$month.'-'.$day);
+        return Carbon::parse($year . '-' . $month . '-' . $day);
     }
 
     public function hasBalance(string $amount = '0.01'): bool
@@ -162,13 +162,26 @@ public function startTransfer(self $to, string $amount, string|null $description
         return $this->balance;
     }
 
+    public function getCostPrice(string $price): string
+    {
+        $this->load('user_group');
+
+        if (!$this->user_group) {
+            return $price;
+        }
+
+        return $this->user_group->getCostPrice($price);
+    }
+
+
     /**
      * 扣除费用
      *
-     * @param  string|null  $amount
-     * @param  string  $description
-     * @param  bool  $fail
-     * @param  array  $options
+     * @param string|null $amount
+     * @param string      $description
+     * @param bool        $fail
+     * @param array       $options
+     *
      * @return string
      */
     public function reduce(string|null $amount = '0', string $description = '消费', bool $fail = false, array $options = []): string
@@ -177,7 +190,7 @@ public function reduce(string|null $amount = '0', string $description = '消费'
             return $this->balance;
         }
 
-        Cache::lock('user_balance_'.$this->id, 10)->block(10, function () use ($amount, $fail, $description, $options) {
+        Cache::lock('user_balance_' . $this->id, 10)->block(10, function () use ($amount, $fail, $description, $options) {
             $this->refresh();
 
             if ($this->balance < $amount) {
@@ -210,10 +223,11 @@ public function reduce(string|null $amount = '0', string $description = '消费'
     /**
      * 增加余额
      *
-     * @param  string|null  $amount
-     * @param  string  $payment
-     * @param  string  $description
-     * @param  array  $options
+     * @param string|null $amount
+     * @param string      $payment
+     * @param string      $description
+     * @param array       $options
+     *
      * @return string
      */
     public function charge(string|null $amount = '0', string $payment = 'console', string $description = '充值', array $options = []): string
@@ -222,7 +236,7 @@ public function charge(string|null $amount = '0', string $payment = 'console', s
             return $this->balance;
         }
 
-        Cache::lock('user_balance_'.$this->id, 10)->block(10, function () use ($amount, $description, $payment, $options) {
+        Cache::lock('user_balance_' . $this->id, 10)->block(10, function () use ($amount, $description, $payment, $options) {
             $this->refresh();
             $this->balance = bcadd($this->balance, $amount, 4);
             $this->save();
diff --git a/app/Models/UserGroup.php b/app/Models/UserGroup.php
index 9355848..e4c3597 100644
--- a/app/Models/UserGroup.php
+++ b/app/Models/UserGroup.php
@@ -60,4 +60,15 @@ public function setTempGroup(User $user, self $group, Carbon $expired_at): User
 
         return $user;
     }
+
+    public function getCostPrice(string $price): string
+    {
+        if ($this->exempt) {
+            return '0';
+        } else if ($this->discount !== 100 && $this->discount !== null) {
+            $price = bcmul($price, bcdiv($this->discount, '100', 4), 4);
+        }
+
+        return $price;
+    }
 }