$55.43 – Color As pictured show, Hot Water Temperature 30-60℃, Waterproof Grade IPx4, Rated Frequency 50Hz, Rated Voltage 220V, Power Cord Length 97cm/38.18inch, Use Pressure 0Pa, Material ABS plastic+Stainless steel, Power 3500W, Plug EU.
I have checked all old coupons and price is $55.43 for 3500W 220V Mini Electric Water Heater Tankless (in Banggood). Basically copy coupon, view price history or create e-mail price alert. Do you want to know what the best price is?
Latest coupon and price update (UTC):
Banggood ($55.43)
Banggood warehouse is located in China. I have no active coupons for you right now. Price? From what I can see this price is higher than average price ($31.32).
Link: Banggood product page
Price: $55.43
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG250ccd, BG26776b, Cuponation9, BG0129d3, BG524ceb, BG735a15, BGRFANSD01, BGNINEF42, BGd2902b, BGdfbf61, BG5d9482, BGb2361c, BG69967f, BG02b07a, BG55e622, BG589b2e, BGf625a4, BG8FORMULAMX
(these coupons are old, so probably won’t work)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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 3500W 220V Mini Electric Water Heater Tankless. The lowest price was: $28.99.
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)).