I have just checked coupons. The lowest price I could get is $14.99 for HC 810 RTR 2.4G RC Boat (in Banggood). Just check coupons out (with price alert and history). Do you want to know what the best price is?
Latest coupon and price update (UTC):
HC 810 RTR 2.4G RC Boat Colorful Paddle Remote Control Rowing LED Lights 360 Driving Dual Modes Waterproof Ship Underwater Balance Vehicles Models Toys – Blue
Banggood ($14.99)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Is it a low price? From what I can see this price is higher than average price ($12.66).
Link: Banggood product page
Price: $14.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
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
Do you need price history chart (for all/most countries) for HC 810 RTR 2.4G RC Boat? There we go.
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)).