Price history, coupons and price alert are available on this page. Best price?
Color: Black (The red transmitter also can use black color. It will get another new view.), Design for 18650 Battery, Item name: Battery Cap, Suitable transmitter: Taranis X-Lite, Brand name: Frsky, Quality materials with a glossy surface treatment
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. ($17.99): bGhOnEy10
2. ($17.99): BGTT10
3. ($17.99): BGSS10%SW
4. ($18.59): BGAFF7OFF
this code has to be applied 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): BGXLiteCap, aff7off, BGXLCap, BGfrsky10, BGaDmITAd, BGRCCD30, BGFRSKY15, bgchinafest, FBCOUPON1
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for FrSky Taranis X-Lite RC Battery Cap Pair is here.
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)).