Aliexpress
Click here… to search for KCASA KC-TP400 Pen Shape Thermometer on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (2.88 USD): BGBBQTT288
Coupon (4.09 USD): AFfbG10
Coupon (4.09 USD): affbg10
Coupon (4.23 USD): aff7off
(CouponsFromChina.com tip: apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): 502C6B, vipupgrade8, 5350f6, TTxBG10, bgssaff9
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for KCASA KC-TP400 Pen Shape Thermometer? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).