Aliexpress
Click here… to search for Hawkeye Firefly 8S S009R Battery 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 (16.89 USD): BGJON8
Coupon (16.89 USD): BGRCParts8
Coupon (16.89 USD): BGMatt2022
Coupon (16.89 USD): BGToys8
(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): f62884, Parts8, 2019SPEDM, bgssaff9, BGBCFPV, BGBCBG10, 502C6B, BGOTC21, BGBFAFF2019, BGCITYADS2019, 2020CNY, BGVDay10%off, BGTT10, bGhOnEy10, BGFPVS10, BGSS10%SW, BGRC902, BGAFF10OFF, BG11SHOP, BGDAVIS, BGGAL8, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG8RCToy, BGJUNEGSG9, BGRCT10, TTSUMMER8, Cuponation9
(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 Hawkeye Firefly 8S S009R Battery.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).