Most affordable tester I've seen is the T-check. (Fermented Fruitz and a few others have this one. It's the "affordable' option for a home/hobby level tester that is accurate enough)
tcheck.me
Next up is the MyDX device at around $1000. (don't know if it does what i need. I belive from my research I would go with the T-check instead.)
www.mydxlife.com
After that you're into the pro ranks with things like the Purpl Scientific: $1500( I learned about this one from the Gnome Genetics owner and AFN member FullDuplex)
www.purplscientific.com
@derek420colorado @Fermented_Fruitz @FullDuplex - These are the guys I've bugged about this same issue.
I trust all three of them for correct and accurate information. Again, gauge your level and needs. I do think spending a decent amount is needed for accuracy and consistent results.

tCheck - Home Cannabis Potency Tester | THC and CBD Potency Tester
tCheck is a home cannabis testing device that makes it simple and quick to measure the THC potency of your infusion, concentrate, or raw flower.

Next up is the MyDX device at around $1000. (don't know if it does what i need. I belive from my research I would go with the T-check instead.)
MyDx | Portable Chemical Analyzer | CDX
Empower your health with MyDx™. Advanced portable analyzers measure chemicals in food, water, and cannabis, providing real-time results for healthier life.

After that you're into the pro ranks with things like the Purpl Scientific: $1500( I learned about this one from the Gnome Genetics owner and AFN member FullDuplex)
Purpl Scientific | Measure Cannabis Potency Instantly
Welcome to Purpl Scientific, the creator of the Purpl PRO, a portable testing device that measures cannabis potency with instant results.

@derek420colorado @Fermented_Fruitz @FullDuplex - These are the guys I've bugged about this same issue.
I trust all three of them for correct and accurate information. Again, gauge your level and needs. I do think spending a decent amount is needed for accuracy and consistent results.