Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (21.59 USD): BGWT15
(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): BG01f324, BG21ceb6, BG00b46c, BGa06b21, BGe5c9fb, BG788b04, BGa0b8da, BGDRB18, BGd7204f, BG09111a, BGHU1741
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Drillpro 12pcs 1/4 Inch Shank Router Bits Set.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).