Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (624.00 USD): Sports23q1
Coupon (651.73 USD): BG589b2e
(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): BG3a3eb5, BGa5bea4, BG93d003, BGissamWW, BG2c373e, BG4492f3, BG92b4bf, BGe46870, BG4c6e9d, BG0aaea5, BG7055ab, BG13178f, BG81d5f0, BG2cf2d8, BGe436e7, BGty712is, BGfc8a9a, BGISSAM469, BGissam38999, Cuponation9, BG79e08c, BG24c894, BGissam15wts, BG94ba1e, BG073996, BgGoodie9, BGc363fd, BG00c906, BG8OFFCOUPON, TTBLACK5, JanBGCoupon8
(these coupons are old, so probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for Aqua Marina BLUEDRIVE 12V Electric Underwater Booster? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).