Which drug test strips work the best?

I'm looking for drug test strips, not sure which to buy. This is what I've found:

From Amazon

1. INSTANT Single Panel Drug Test Kit - Test For THC (marijuana) - 10 pk - NewMed Diagnostics - $10.95, sale $6.79 and another for $3.15
2. Drug Test - Marijuana (THC) 10 Urine Test Strips - Devon Medical - $14.99, sale $9.95
3. Wondfo WDTH-101 Devon Medical, Marijuana (THC) Urine Test Strips, Pack of 5 (Look like above) - $5.95
4. Drug Test - Marijuana (THC) 25 Urine Test Strips - Devon Medical (look different) - $22.95
5. Wondfo THC- 10 Devon Medical - (Look like above) - $9.99, sale $9.95

From Ebay, they sometimes dont say who the manufacturer is, so I had to do some research.
6. Devon Medical - 5/$6.25, 10/$12.00 and 25/$20.00 (Look like #4 and #5)
7. Devon Medical 10/$14.95 (Look like #2 and #3)
8. Devon Medical - 25/$32.26 5/$2.99 1/$0.99 (a third type)
9. InVitro Diagnostics (Canadian) - 20/$29.99, 5/$9.59
10. Medical Disposables - 1/$1.85
11. One Step (ClinicalGuard?) - 10/$8.99
12. THC/Amph Test kit - (Medical Disposables?) - 20/$69.50AU
13. HomeHealth-UK - 10/$8.93

Should I just get the most expensive one? InVitro Diagnostics, Medical Disposables, and the expensive Devon Medical?
Is there a better way to go about picking a test? I plan to get 2 or 3 brands and do some experiments.

Am I posting this in the wrong place?

The only thing I've read about picking a drug test is to pick something more than $1 a strip, but as you can see, possibly different versions of the same strip from Devon Medical vary above and below $1. Some advice from someone knowledgeable would be appreciated. Thanks.