According to my DB the lowest price is 22.49 USD for Rainproof Power (in Banggood). Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Latest coupon and price update (UTC):
Banggood (22.49 USD)
Banggood warehouse is located in China. Isn’t it too expensive? Well, this price is higher than average price (16.99 USD) I am tired of searching coupons, but I found one for you…
Link: Banggood product page
Price without coupon: 24.99 USD
Coupon (22.49 USD): BGAMMT03
(CouponsFromChina.com tip: this code has to be applied in your 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): BG20017a, BGCarEle5, BGd77e61, BGSCM11, BG845979, BGLMQ15, BGCAR639
(these codes were not working in latest coupon update, but you can check them out anyway)
Aliexpress
Click here… to search for iMars 200W LED Rainproof Power Supply 12V/24V on Aliexpress
Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for iMars 200W LED Rainproof Power Supply 12V/24V.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).