I have just checked coupons. The lowest price I could get is $75.99 for LILYGO T-Deck ESP32-S3 LoRa 2.8 inch LCD Development Board (in Banggood). Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Latest coupon code price check (UTC time):
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
Banggood ($75.99)
Banggood warehouse is located in China. There are no coupons available at this moment in Banggood. Is it a reasonable price for this item? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $55.77)
Link: Banggood product page
Price: $75.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGBFDAY8, BG0e5f45, BGdcfb16
(these coupons are old, so probably won’t work)
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)).