Go down and check coupons out. Remember to check price history if it is available. What is best price?
128* 64 resolution, Size: 158 * 150 * 58, Display: 1.7-inch LCD display, Working voltage: DC5-DC9V (factory with 4 * AA battery box, Firmware: OpenTX, Version: Left Hand Throttle, Gimbal Type: Potentiometer, Channels: up to 16 channel output, 2s Lipo recommended, Upgrade method: USB online upgrade, Weight: 342g (without battery), JR/FrSKY compatible module bay on rear side, Radio MCU: STM32F205VET6 (512kb), batteries not included)
Aliexpress
There’re some similar (or not) items on Aliexpress
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 China.
Link: Banggood product page
1. ($82.71): bgssaff9
2. ($83.62): Parts8
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): JT12, 20OFFRSF, 502C6B, TTxBG10, 2019SPEDM
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Jumper T12 OpenTX RC Transmitter with JP4-in-1.
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)).