Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
Diameter 150mm/7″, Color Orange / White / Black, Thickness 45mm/1.77″, Material Sponge, Thread M14, Max speed 3000rpm
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 and price update (UTC):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($10.79): BGAMMT03
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG8ac7a4, MVC8SPRING, 2203ActiesNL, BGAUTO22, BG00c906, Cuponation9, 9OFFSUMMER, BGSCM75, BG589b2e, BGSCM11, BG3b2d36, BGCRT313, BGCAR639
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for M14 150mm Car Buffing Polishing Sponge.
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)).