Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (6.44 USD): BGAFF10OFF
Coupon (6.44 USD): bGhOnEy10
Coupon (6.59 USD): Parts8
(CouponsFromChina.com tip: you should apply the coupon in your 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): aff7off, rchobbies8, e2bcea, TTxBG10, bgssaff9, AFfbG10, affbg10, 502C6B, BG12MRP, BGCITYADS2019, BGGEPPart, BGMPB2020, BGdragonBoat, BGSS10%SW
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Micro Minim RC OSD board? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).