Beam width -3dB at +/- 45 degrees (H + V) (90 degree total), 8dBi gain, 5.8GHz ISM Band, Weight 7g, Impedance 50 ohms, F/B Ratio >356dB, VSWR < 1: 1.35 at 5800MHz. Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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.
Link: Banggood product page
1. ($9.22): BGTT10
2. ($9.22): bGhOnEy10
3. ($9.24): 13f142
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): bgshOOp10
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for ImmersionRC Mini Patch 5.8GHz LHCP FPV Antenna is here. The lowest price was: $5.99.
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)).