Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (24.53 USD): BGherra
Coupon (24.53 USD): BGWELDTOOL
(CouponsFromChina.com tip: this code has to be applied in your 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): AFfbG10, 502C6B, 0e7f33, FBCOUPON1, BGTool15, BGRUS15
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for 60W 220V Electronic Soldering Iron Kit.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).