Max. Power: 50w, Color: Black, Weight: 8.6g, Length: 78±3mm, Connector: RP-SMA, Gain: 5dBi, Max. Dia.: 22.4±1mm, Polarization: Circular Polarized, Radiation: Omni, Impedance: 50Ω, VSWR: <1.5: 1, Brand name: Eachine, Item name: pagoda antenna, Frequency: 5.8G, Min. Dia.: 11.8±1mm. Basically copy coupon, view price history or create e-mail price alert. You probably want to know what is the best price?
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 coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
1. ($13.50): BGRCEachine
paste coupon code in your cart and click Apply 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): BGEachine10
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Eachine 5.8G 5dBi 50W Pagoda RC Antenna RHCP RP-SMA? There we go. The lowest price was: $12.86.
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)).