I have checked all old coupons and price is $5.99 for 6Pcs M2 High-Speed Steel Center Drill Bits Set (in Banggood). Go down and check coupons out. Remember to check price history if it is available. What is best price?
6PCS M2 High-Speed Steel Center Drill Bits Set Metalworking Tools 60-Degree 1.0-6.0mm Countersink Lathe
Latest price update (UTC time):
Banggood ($5.99)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. Price? It looks like it’s a good price (lower than average ($6.72)).
Link: Banggood product page
Price: $5.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGWDT15
(system checks these coupons on every price check (like once per 24 hours), 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
Do you need price history chart (for all/most countries) for 6Pcs M2 High-Speed Steel Center Drill Bits Set? There we go.
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)).