[FrankenMauser]

Snap-On wrenches are good, but overpriced and unnecessary for the intended use.

For AR barrel nuts, Harbor Freight should be good enough.
Yea, they're cheap. But they've also been tested by quite a few different organizations and people, and been shown to be as accurate and repeatable as Craftsman and 'basic' Snap-On torque wrenches.
They do get impacted more by the spring relaxing if left set at a high torque setting for storage, but if you don't store at a high torque setting, it doesn't really matter (and it shouldn't be done with any torque wrench).



Texas45 makes a good point, too. If a torque wrench isn't recalibrated periodically, it doesn't matter how good it was to start with.
When I was still working on the flightline, we went through torque wrenches like candy -- nearly all Snap-On. One drop, even inside the plastic case, and a torque wrench has to be considered bad (legitimately -- I saw them off by as much as 20% from a 4 foot drop). Even just normal use - four to twelve bolts, one or two times a day, at 30-70% of rated value - usually had them off by 3-5% at our mandated yearly recalibration, sometimes they were off by 10-15% or had big problems with repeatability.
If you need accuracy, you need regular calibration.