Power Supply USB 0.5A, Color White, Flash 16Mb, Standard IEEE 802.11b/g/n, Frequency Band 2.4GHz, SDRAM 64Mb, Transmit Power 20DBm MAX, Model BW-NET4, Power Plug USB.
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 Europe 
. Sorry, but there’s no price history in my database.
Link: Banggood product page
1. ($10.99): BGBFZ11
2. ($17.85): 00c906
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGN821D, bgshOOp10, bGhOnEy10, BGN921K, BgcLuBofErtA10, BGNQ21Z, BGRBWNET4, BG48078, BGN1221J, 10%ForNewBW, BGCuponation10, BGNC0781, BGN0478, BGN0678U, 13f142, BANGGOODSD
(probably won’t work, but you can try them out)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – BlitzWolf BW-NET4 Wifi Repeater 300Mbps ($-3)
Price history and price alert
There is only one database record (it was for $9.49), so you can’t see price history chart.
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)).