Aliexpress
Click here… to search for XTAR ST2 Battery Charger on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (49.79 USD): BGTorch4
(CouponsFromChina.com tip: apply it 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): BGST2, FINst2, EYBG, BGTORCH, 502C6B, BGBFCR41, FST2, bGhOnEy10, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10, BGFLS15, BGAFF10OFF, BGCuponation10, 4BLF, BGHONEY2110, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for XTAR ST2 Battery Charger.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).