Aliexpress
Click here… to search for ZOP Power XT60 14.8V 4S 1500mAh 70C RC Battery on 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 (26.42 USD): BGRCBC11
Coupon (27.62 USD): Parts8
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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, Charger12, CFCBG, BGBFCR02, BGCITYADS2019, AFfbG10, BGVDay10%off, BG10BC, BGAFF10OFF, BGTT10, bGhOnEy10, BGCuponation10, BGBCSpring1, BGDAVIS, BGHONEY2110
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for ZOP Power XT60 14.8V 4S 1500mAh 70C RC Battery.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).