Aliexpress
Click here… to search for 2500mAh Electric Hot Melt Glue Gun on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (33.99 USD): BGHPT15
Coupon (35.99 USD): BGGines
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): BGe8b7f3, BGcd67ad, BG5c6e66, BGb8bbf9, BGPHOOL8, BG74fb5f, BG2cd043, BGf56e24
(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 2500mAh Electric Hot Melt Glue Gun? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).