Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
Coupon (12.75 USD): BGherra
(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): TA12, BGAT18, BGVDay10%off, BG2020NS, bGhOnEy10, BGAFF10OFF, BGBFCR32, BGDB0701
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for JIMI 4Pcs 6/8mm Drill Bits For Ceramic Wall Glass Concrete.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).