Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Well, there is one coupon available right now.
Link: Banggood product page
Coupon (314.06 USD): BGRepair63
(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): TTxBG10, DVRCAMERA10, BgAuMotor, AM15prime, BGAnniversary, AMPrime01, Automo, BG11X431, BGLAUNCH, Automo1, BGBFCAR01, BGLAUNCH1, BGCHRISTMAS, BG20CAR, BGAutos, bGhOnEy10, BGJulyCAR01, BG219219, BG239239, BGCARELEC, BGAFF10OFF, BGCuponation10, BGwhielabel, BGHRepair2, BG10OFFAFF1
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for LAUNCH X431 CRP429C OBD2 Tool.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).