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 (87.12 USD): tRaDetRaCKeR
Coupon (88.07 USD): 2203ActiesNL
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): Terence, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for CaDA C61018W 1696Pcs 1/9.5 DIY Building Blocks without Electronic Parts is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).