Latest update shows that 9g Micro Plastic Gear costs 8.99 USD (in Banggood). You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Latest coupon and price update (UTC):
Banggood (8.99 USD)
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now… Is it expensive? From what I can see this price is higher than average price (7.06 USD).
Link: Banggood product page
Price: 8.99 USD
Old coupons (from the oldest to the newest): BGToys8, BGMatt2022, BG25d4e7, BG589b2e
(these coupons are old, so probably won’t work)
Aliexpress
Click here… to search for Racerstar SG90 9g Micro Plastic Gear Analog RC Servo on Aliexpress
Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for Racerstar SG90 9g Micro Plastic Gear Analog RC Servo.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).