Aliexpress
Click here… to search for 35 Pcs/pack Gateron Switch Pro Mechanical Keyboard Switch on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
Coupon (15.83 USD): BGff5312
(CouponsFromChina.com tip: just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGc0ac93, keyboardMVC, BG609e1d, Cuponation9, BGKBandmos12
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for 35 Pcs/pack Gateron Switch Pro Mechanical Keyboard Switch is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).