Some time ago I bought a "2000 lumens" flashlight from China on Amazon for $15. It was a lie as it's only about 400-450 lumens. It uses 2x18650 Li-Ion batteries. It's not a bad flashlight, just that it's not 2000 lumens.
I did some research and found the Candle Power forum so I joined them and asked about it. Very knowledgeable people and I learned a lot about flashlights, especially about LEDs. I asked for suggestions for a light and got several.
I decided on this Nitecore P36 which I found on Amazon for $82 and it uses 2x18650 as well. The batteries I got are one of the best, Simom made by Panasonic.
This is the real 2000 lumens flashlight and it's got some weight to it because of the heat sink.
I shone it in my back yard at the corner about 20 yards away. I used my camera without the flash so it's a little shaky but you can see how bright this sucker is.
I love this flashlight and it has some cool functions and ease of use. Well worth my money.
By the way, Amazon was the cheapest I found as the other sites were selling it for $130 to $200.