Model AC1200, Wireless standard IEEE802.11ac/a/n/g/b, Interface USB3.0, Brand ISIGAL, Main chip RTL8812BU.
Basically copy coupon, view price history or create e-mail price alert. 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. Only one coupon available!
Link: Banggood product page
1. ($21.61): BG589b2e
coupon code has to be applied in shop’s 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): BG3487fc, BG00c906, 8BGwbg2204, tRaDetRaCKeR, BG368a43, BG81b97a, BGb6182e, BGWSCYT1, BGde2f67, BGc209d1
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for iSigal AC1200 Gigabit Wireless Network Card. The lowest price was: $11.99.
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)).