According to my DB the lowest price is 7.79 USD for 20W 2-Port PD3.0 QC3.0 (in Banggood). Basically copy coupon, view price history or create e-mail price alert. What is best price?
Latest coupon code price check (UTC time):
Banggood (7.79 USD)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Price? Cool, average is 9.07 USD, so current price is lower!
Link: Banggood product page
Price: 7.79 USD
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGHONEY2110, BGf349cb, BGf015b6, BG89db52, BGecaf15, BG7d61b3, BG049b7c, BG02307e, BG8b1220, BGf73409, BGa17a7c, 13f142, BGa787c6, BGa5d67d, BG8e7512, BGac2369, BG483696, BGd5569c, BGB294C8, BG85d5c6, BG59486c, 2022ACTIESNL, BG60f247, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG3facf2, BGJUNEGSG9, BG8ReviTrage, BG8c457b, BGXIFD139, BG727bd5, BG64a8c6, BGe69c80, BG876d17, BGd4c235, BG04a8fd, BG589b2e, BG6015ea, BGe66da2
(probably won’t work, but you can try them out)
Aliexpress
Click here… to search for BlitzWolf BW-S20 20W 2-Port PD3.0 QC3.0 Wall Charger on Aliexpress
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for BlitzWolf BW-S20 20W 2-Port PD3.0 QC3.0 Wall Charger is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).