Camera 20MP Industry 3.5X-90X Trinocular Microscope Camera [EU] (Banggood, Aliexpress: 1x Microscope Bracket, 1x Trinocular Stereo Zoom Head, 1x Focusing Rack, 1x Power Supply Adapter, 1x Dust Cover, 1x 144-LED Ring Light, 1x HDMI Video Camera(20.0MP), 1x 0.5X Microscope Auxiliary Objective Lens(Working Distance 165 mm), 1x High Temperature Resistant Working Pad, 1x Pair of Super Widefield 10X20MM Eyepieces, 1x C-mount Adapter, 1x Pair of Eye-Guards, 1x 1.0X Microscope Auxiliary Objective Lens(Protection function), 1x 2.0X Microscope Auxiliary Objective Lens(Working Distance 40 mm) (the best price with coupon)).
Just check coupons out (with price alert and history). What is best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
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 Europe 
. I don’t really know if this price is reasonable, coz there’s no price history in my DB. Well, there is one coupon available right now.
Link: Banggood product page
1. ($360.89): BGGines
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGd1f09a, BGd06437
(probably won’t work, but you can try them out)
Price history and price alert
There is only one database record (it was for $309.99), 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)).