ATM you can buy 6.35mm Shank Router Bit 1/2inch 12.7mm 4pcs for $10.99 (in Banggood). Go down and check coupons out. Remember to check price history if it is available. What is best price?
6.35mm Shank Router Bit Pattern Flush Trim Blade Bearing 1/2″ Straight End Mill Slotting Milling Cutter For Woodworking Dia 12.7mm
Latest price update (UTC time):
Banggood ($10.99)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. What about the price? From what I can see this price is higher than average price ($9.49).
Link: Banggood product page
Price: $10.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
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
Here is price history (for all/most countries) for 6.35mm Shank Router Bit 1/2inch 12.7mm 4pcs.
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)).