You can create price alert here, copy coupons and view price history. What is best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Power 240W, Type Car Washer, Handle Material Engineering Materials, Charger Voltage AC 100-240V 50/60Hz, Outlet Pressure 30Bar/435PSI, Water Flow 4 L/Min, Head Tip Material Copper, Length Of Water Pipe 5 Meter, Input Voltage 24V
Banggood
Banggood warehouse is located in Europe 
. I don’t really know if this price is reasonable, coz there’s no price history in my DB.
Link: Banggood product page
1. ($34.99): BG71d3dd
2. ($59.99): BGd86564
3. ($81.47): BGherra
4. ($81.47): BG123F2021
put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Price history and price alert
Not enough data to show price history chart… $34.99 is the only recorded price. It was not cheaper than that since we have saved it in DB.
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)).