I have just checked coupons. The lowest price I could get is $49.99 for LILYGO T-Deck ESP32-S3 LoRa 2.8 inch LCD Development Board (in Banggood). You can create price alert here, copy coupons and view price history. Best price?
LILYGO® T-Deck ESP32-S3 LoRa 2.8 inch LCD Development Board LoRaWAN Long Range 433MHz 868MHz 915MHz with WiFi bluetooth Module Board – White 433MHz
Latest coupon code price check (UTC time):
Banggood ($49.99)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. Is it a low price? I have never seen better price than the current one in CouponsFromChina database, so it’s the best!
Link: Banggood product page
Price: $49.99
This is the best price ever noted in my database!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGBFDAY8, BG0e5f45, BGdcfb16
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for LILYGO T-Deck ESP32-S3 LoRa 2.8 inch LCD Development Board.
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)).