When I was updating this page, then coupon price was 137.99 USD for TX-850 Lite Metal Detector (in Banggood). Get coupons, create price alert or check price history out! What is the best price?
Latest coupon and price update (UTC):
Banggood (137.99 USD)
Banggood warehouse is located in China. Price? Well, this price is higher than average price (124.49 USD) There is one great coupon!
Link: Banggood product page
Price without coupon: 145.99 USD
Coupon (137.99 USD): BGESJY8
(CouponsFromChina.com tip: apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG0224MD, BGherra, BG0e75a9, BG20236Tool, BGTOOS729, BGSPRING8OFF, BGHONEYSP
(these coupons are old, so probably won’t work)
Aliexpress
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for TX-850 Lite Metal Detector is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).