You can get MT-M039 31-in-1 Screwdriver Set for $7.99 using coupon code (in Banggood). Price history, coupons and price alert are available on this page. You probably want to know what is the best price?
MT-M039 31-in-1 Screwdriver Set Double-Sided Magnetic Tip Hand Tools Magnetic Screwdriver Set Screwdriver Bits
Latest coupon and price update (UTC):
Banggood ($7.99)
Banggood warehouse is located in China. I couldn’t find any coupon for this product on latest product update. Low/high price? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $7.37)
Link: Banggood product page
Price: $7.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG20236Tool, BG589b2e
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for MT-M039 31-in-1 Screwdriver Set is here.
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)).