Just check coupons out (with price alert and history). Do you want to know what the best price is?
Working voltage: DC4.5-DC18V, Item Name: T8SG Transmitter, Transmitter Module: Four in One High Frequency Module(CC2500 CYRF6936 A7105 NRF2401), Transmit power: maximum 22dbm (transmit power adjustable), Upgrade method: USB online upgrade, Antenna gain: 2db(detachable antenna, Rocker way: non-contact 3D space vector Hall joystick, Weight: 338g(without battery), Working current: 88Ma@8. 4V, Color: Black, Transmission frequency: 2.400GHZ-2.7GHZ, 128*64 resolution, Remote control distance: >2km@ 22dbm, Size: 158x 150x 58 mm, easy modification), Number of channels: up to 12 channels(depending on the receiver), Open source firmware, Display: back lit LCD display, JR/FrSKY compatible module bay on rear side
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): Email5, 2020CNY, BGVDay10%off, BGJPTX, BGJPTX8, BGT8SGPO, BGJPTX13, BGTX8, BGTT10, BGJPTX8WK, bGhOnEy10, BGRDJP8, BGTXT8PRO, BGT8CLE, BGTXJP8G, BGT8SP, BGJPT865, BGSS10%SW, BGJPT8CZ, BGT8SGAG, bgshOOp10, BGJPTXAS, BGJPTXYB, 7d18f7
(there’s a little possibility that old coupon will work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – JumperTX T8SG RC Transmitter [EU] ($-3)
Price history and price alert
Here is price history (for all/most countries) for JumperTX T8SG RC Transmitter.
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)).