According to my DB the lowest price is $19.99 for Zeblaze GTS 3 Plus Smart Watch (in Banggood). You can create price alert here, copy coupons and view price history. Best price?
[2023 World Premiere]New Zeblaze GTS 3 Plus 2.15 inch Ultra-large 415*505pixels HD AMOLED 24H Heart Rate SpO2 Hifi bluetooth Phone Call BT5.2 Smart Watch – Black
Latest coupon and price update (UTC):
Banggood ($19.99)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? Low/high price? Pretty good price – average ($21.78) is higher than current one!
Link: Banggood product page
Price: $19.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
1. (25.7.2024, $17.99): BGRJU7GTSP
Item: Zeblaze GTS 3 Plus Smart Watch
Countries: Greece, Portugal, Spain
Old coupons (from the oldest to the newest): BG374e3d, BGspringG379, BGREUZG3L, BGRJU6ZBG3, BG076b6e, BGZLE17, BGac7e94, BG7a8aeb
(these codes were not working in latest coupon update, but you can check them out anyway)
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
Price history (for all/most countries) for Zeblaze GTS 3 Plus Smart Watch 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)).