I have just checked coupons. The lowest price I could get is $17.99 for XD 1080P FHD Mini Camera (in Banggood). Basically copy coupon, view price history or create e-mail price alert. Best price?
XD 1080P FHD Mini Cameras IR-cut Night Vision Security Protection Micro Cam Motion Detection Loop Video Mobile Monitoring Video Recorder Camera – With battery
Latest coupon code price check (UTC time):
Banggood ($17.99)
Banggood warehouse is located in China. Coupons for XD 1080P FHD Mini Camera? Nope, there’re no coupons in Banggood. Is it cheap? Well, this price is higher than average price ($15.34)
Link: Banggood product page
Price: $17.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG589b2e
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for XD 1080P FHD Mini Camera.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).