Just check coupons out (with price alert and history). Let’s see what best price is ATM.
USB 3.0, Converts any 9.5mm & 7mm 2.5” SATA HDD/SSD into an external hard drive
Aliexpress
I could not find it 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 China. I found coupon for you. Check this out.
Link: Banggood product page
1. ($17.10): BANGGOODSD
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 502C6B, TTxBG10, BG3CSUM, AFfbG10, affbg10, BGggy86b, BGBFAFF2019, BGVDay10%off, BGAFF10OFF, BGSS10%SW, BGdragonBoat, bGhOnEy10, BgcLuBofErtA10, BGN94YD, BGCuponation10, BGHONEY2110, BGN0679R, BG7db5e3, BG0ca975, 2022ACTIESNL, BG4249c7, BG00c906, BG91eb6c
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – MantisTek Mbox 2.5 USB3.0 Hard Drive Enclosure [EU] ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for MantisTek Mbox 2.5 USB3.0 Hard Drive Enclosure.
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)).