Welcome fellow flashlight enthusiasts! (I think we should lobby for a flashlight section in the Gear category 
)
Someone famous once said:
There are lies… damn lies… and then there’s
statisticslumen counts
For background, lumens is a measure of the total light OUTPUT. And candela is the measure of all the light that hits ONE SPOT.
Lumen count is only a piece of the story, that needs to be balanced with candela. Other criteria includes runtime in total, runtime at “max” output, and UI (aka buttons).
So you can have a light like the Surefire DualFuel with 1500 lumens and folks complain that it doesn’t throw very far. Then a light like the Modlite OKW comes along with 680 lumens (less than half) and can easily throw across a football field. You get that balance by the reflector material, shape, the glass/plastic lens, etc which “shapes” the light output.
I think that Streamlight makes “most” of their lights in the USA, but I am pretty sure their HL-X which is a fantastic ~$100 rifle light is made in China. Olight definitely make all their stuff in China. Surefire, Modlite, and Cloud Defensive are AMAZING lights, but are definitely way more expensive.
As to whether 300lumens is “enough”? It depends on what you’re doing with it. 300 lumens for an EDC-type light is plenty. For defensive weapon use, IMO, the minimum is ~500lumens, but candela plays a HUGE part here.
And definitely… avoid knockoffs. If you buy from Amazon (which is increasingly becoming not a good place for this) make sure its a reputable seller. I try to buy direct from the manufacturer’s website when possible.