$13.99 – Material: ABS, , Output Voltage: 3.7V / 10A, Color: Gray/Green/Red, Idling Time: 2 hours, Package Weight: Approx. 183g, Input Voltage: DC 5V USB, Polishing Working Time: Up to 1 hours, Choose：Standard Model / Deluxe Model （optional）, Collet Chuck Diameter: 0.5-3.2mm, Rated Power Input: 10W, No-load Speed: 5000/10000/15000 r/min.
When I was updating this page the price was $13.99 for USB Charging 10W Grinding Machine (in Banggood). Get coupons, create price alert or check price history out! Do you want to know what the best price is?
Latest coupon code price check (UTC time):
Banggood ($13.99)
Banggood warehouse is located in China. Coupons for USB Charging 10W Grinding Machine? Nope, there’re no coupons in Banggood. Isn’t it too expensive? This price is higher than average price ($13.32) for this item.
Link: Banggood product page
Price: $13.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG589b2e, BGPT07
(these coupons are old, so probably won’t work)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for USB Charging 10W Grinding Machine. The lowest price was: $12.99.
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)).