Opening range: 16-68mm, Overall length: 200mm, Material: Aluminium alloy.
Basically copy coupon, view price history or create e-mail price alert. Best price?
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. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
1. ($5.20): BG589b2e
coupon code has to be applied in shop’s 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): BGHTT15, BG20236Tool
(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 200mm Mini Adjustable Spanner Wrench is here. The lowest price was: $5.2.
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)).