Model: GK100S, 3. Keys Amount: 104keys, 4. Connection: USB wired, 5. Anti-ghost key: Any 6 Keys/ NKRO, 6. Keycap: Double Shot injection Molding ABS Keycaps, 7. Click life: Up to 50 million clicks, 8. Rated voltage: DC 5V/250mA.
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 coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
1. ($41.39): TTxBG10
put item in your cart and apply coupon code there 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): be472a, 502C6B, e18b44
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for HP GK100S NKRO Blue Switch Keyboard is here. The lowest price was: $35.55.
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)).