Aliexpress
Click here… to search for Digoo DG-QB01 IP Camera 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 (16.99 USD): BGDG15
Coupon (16.99 USD): BGSAMH
Coupon (18.59 USD): aff7off
(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): 1999QB01, 0404digoo, 16QB01, affiliate6, BGDigoo15%, BGaDmITAd, bgchinafest, BGCITYADS2019, bGpAnDacHeCk, 2020CNY, BGVDay10%off
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Digoo DG-QB01 IP Camera.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).