Octa-core, CPU: MediaTek Helio G35, 4x A53 @ 2.3GHz + 4x A53 @ 1.8GHz, ROM: 64GB eMMC 5.1, up to 650MHz, OS: MIUI (Based on Android), GPU: PowerVR8320, RAM: 3GB LPDDR4X, Card Extend: Supports an external TF card up to 512GB (VFAT).
Basically copy coupon, view price history or create e-mail price alert. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Hong Kong. We have found one coupon for this product!
Link: Banggood product page
1. ($137.08): BG8OFFCOUPON
put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGR9C64, Email5, BG119C64, BGD11R9C64, 7d18f7, BGBF9C64EE, BGBF9C64UK, BGBF9C64ES, BG019C, BGGSMTRES, BG2RU9C64, BG9CSP, BGCuponation10, 13f142, Promozione, BGa0e405, BG5d7bc3, BG2a4805, BGdc9116, BGc4866c, BGbe26d7, BGd23024, BG2f7241, BG1c1058, MVC8SPRING
(these coupons are old, so probably won’t work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Xiaomi Redmi 9C 3/64GB Global [EU] ($-3)
Price history and price alert
Price history (for all/most countries) for Xiaomi Redmi 9C 3/64GB Global is here. The lowest price was: $99.99.
Price records source(s): Gearbest, 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)).