According to my DB the lowest price is $37.99 for TENGOO HV-13 Heated Vest (in Banggood). Just check coupons out (with price alert and history). What is the best price?
6.Temperature Shift(Manual adjustment), 5.Power Supply: 5V/2A Mobile Power(Not Included), 1.Style: Sleeveless Vest, 9.Energy Saving: 25 ℃ (Blue Light), 8.Comfort: 35 ℃ (White Light), 7.Warm: 45 ℃ (Red Light), 3.Color: black/blue, 4.Size: S/M/L/XL/2XL/3XL/4XL/5XL/6XL, 2.Material: Polyester
Latest price update (UTC time):
Banggood ($37.99)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? Is it cheap? From what I can see this price is higher than average price ($28.39).
Link: Banggood product page
Price: $37.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG5905b5, BGc5bfa9, BG576927, BG42b870, BG589b2e, BGSPW011, BG0fcbe5, BGd96723, BG730fbe, BGCAPITALOS8, BG5ffdb2, BGTYTG12, BGTYTHUR8, BGTYHV13
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Aliexpress
I could not find it 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 TENGOO HV-13 Heated Vest? 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)).