The cheapest U3 memory cards?

What to expect when you buy a bunch of cheap U3 rated memory cards for 5 bucks and they arrive in a plastic bag?

I tested them to find out if the absence of a shiny secure blister really makes a difference.

When I saw the prices of these Eekoo microSD cards, I thought they were some fake U3 re-labeled SDHC. As I just needed some cheap storage for non-critical tasks, I bought a pair of them with the plan to test them anyway on arrival, just in case...

16GB: 4.13€ / 4.59$

32GB: 5.37€ / 5.97$ 

The U3 classification requires a minimum writing speed of 30MB/s, and the only U3 card I have so far, a Kingston 32GB, merely complies with that lower limit.
Time to test the ...eeekoooooo....

I use the following benchmarking utilites with both cards:
CrystalDisk Mark 5 (Windows),
A1 SD Bench (Android),
and...
H2testw (Ach! mein liebes altes Testwerkzeug für Windows!).

To my surprise, the writing performance is well above the U3 threshold, despite the average value from several tests below slightly pulled down, by the USB 3 port and reader under Windows.
I had much better results when measured directly in the Android device (a Lenovo TB8703F).

MicroSD	Average R (MB/s)	Average W (MB/s)
Cheapo 1GB no class	15.00	8.00
Kingston U3 32GB	43.63	31.50
Eekoo U3 16GB	77.63	48.65
Internal Lenovo	48.25	24.32

I should find out soon if these cards are built to last as I decided to use one of them as internal storage for my old Lenovo tablet.