Just check coupons out (with price alert and history). Do you want to know what the best price is?
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 and price update (UTC):
Dotted lines: 2lines.Can set color& width& position, Interface: HDMI(Type A).USB(Type B).TF Card, Power consumption: MAX 0.15W 12V /0.12A, Cross lines: 8lines.Can set color& width& position, Can output with USB at the same time, Mirror: Horizontal vertical mirror, Optical format: 1/2.3 inch, Sensor P’anasonic: 41 MegaPixel / 21 million pixels CMOS, Scale mark lines: 2lines., Packaging size: 160*100*80mm, Sharpness Contrast Color gain: Support, AWB: WB color correction/Auto/Manual, Camera size: 74*74*35mm, Module: FHD216, Video resolution: 1080p@60FPS, Mono Negative: Support, HDMI resoltion: 1920*1080p 60FPS, TF card: MAX 64GB, Exposure: Auto/Manual.AE value can set, Gross weight: 400g, Net weight: 180g, Language: English/simplified Chinese, HDMI scale: Support 4: 3 /16: 9 /16: 10 screen, Image resolution: 41MegaPixel, R.G.B value setting independent, IR remoter: Support, Lens interface: C/CS口, Voltage in: DC 12V 55-21mm size, pixel size: 1.335μmx1.335μm, Can output with HDMI at the same time, USB2.0(Drive free): 1920*1080@30FPS 1280*720@30FPS 640*480@30FPS, Digital Zoom: Support
Banggood
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 7d18f7, 13f142, BG632dd9, BG59d172, BG967d57, BGGines, BG388006, BG5737db, BG3df9eb, BGGRE888, BG7542ce
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Price history (for all/most countries) for 3.5X 7X 45X 90X Double Boom Stand Zoom is here.
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)).