Just check coupons out (with price alert and history). 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 code price check (UTC time):
Color White/Navy, Size 174*68*36mm (x2): Elongation: 209*68*36mm (x2), Product Model DSHJ-S-2111 (A Wire Control/B Wire Control), Rated Voltage 220V~（will also come with a mini&safe adaptor according to your country）, Timing Function 3h / 6h / 9h (Wire Control Version), Executive Standard GB 4706.1-2005, Rated Power 20W, Material ABS, Brand SOTHING, Product Weight 320g
Banggood
Banggood warehouse is located in China. Coupons for Sothing Shoes Dryer PTC Heater? Nope, there’re no coupons in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGNOXP151, BGHUDE31, BGXPDE171, BGAlerabat1, BGISJA241
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for Sothing Shoes Dryer PTC Heater is here.
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)).