Aliexpress
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Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (12.60 USD): Cuponation9
Coupon (13.02 USD): BG00c906
(CouponsFromChina.com tip: apply code in your basket (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, BGVDay10%off, BGAFF10OFF, BGTT10, bGhOnEy10, BGdragonBoat, BGSS10%SW, BgoFErTaSchInA10, BgcLuBofErtA10, BG10OFFAFF, BGwhielabel, 13f142, BG10OFFAFF1, BG4d9120, 00c906, ADMITAD2212, 2022ACTIESNL, Terence, Tabby20, 2203ActiesNL, BG1efeb0, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG71c041, BGd8c503, 9OFFSUMMER
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for DUUTI Portable Bike Pump is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).