Thank you everyone. I never even heard of these lights. I am so glad that people are helpful here! 
On the Mountain Electronics Supfire M6 - 3 x XM-L2, he lists four mod option 2’s.
Pardon my LED ignorance, but what is the difference between the four types?
The mod 2’s are all priced the same.
Mod Option 2 XM-L2 U2 1A
Mod Option 2 XM-L2 T6 3C
Mod Option 2 XM-L2 T6 4C
Mod Option 2 XM-L2 T4 5B1
I often see the numbers after XM-L or XM-L2, but I don’t know what they mean. Are they codes for color? like cool white, neutral white? or are they the type of reflector used?
U2, T6, T4 are brightness bins.
1A, 3C, etc are tint codes. 1A being cool white 3C being neutral white etc.
Much more detail here: Tint, Binning, and CRI Explained (For XM-L LEDs)
I often forget what range of Kelvin the 1A or 3C designation signifies but those last 2 numbers designate what range of white the emitter can be expected to emit.
The XML2 U2 1A is 6500-7000 Kelvin or very cool. 4C is a warmer hue, 3C is warmer than that and the ones with a B tend to be warmest with a higher color rendering index (CRI). But I usually don’t remember all that mumbo jumbo. I know I like 4500 Kelvin so I go to the page on that website where he sells LEDs and look up the description of the emitters and their Kelvin rating and select the one closest to 4500 Kelvin. Tastes are different and some prefer a warmer or cooler hue and RMM of mtnelectronics is just catering to our preferences. I knuckled down and bought the 2nd option with T6 3C. More than I wanted to spend as I am cheap but I know I would take forever to mod it myself and would not turn out as nice. I have always been happy with my purchases there. Good luck.
Thanks everyone for the great info. I have a lot to learn… H)
M6 or M6 with modifications. That will give you a nice set of modes, plenty of light, side clickie, and a safe multiple battery configuration.
http://www.fasttech.com/product/1519900
This is may put out more light, possibly a lot more, but rear clickie isn't as friendly to use, most likely has a terrible set of modes, and batteries in series isn't as safe.
There's also the Supfire L1.
It already has the output you want, but you can get 5000 lumens with a resistor mod. Maybe over 7000 lumens if you install XM-L2 U2's on direct bonded copper mcpcb's.
Even swapping those XM-L's to direct bonded copper stars will get you close to 7000 lumens.
So let's says $63 for the light, $10 for emitters, and a little time with a soldering iron.
Cree's data is only good up to 3A if used with a terrible mcpcb.
and what's the best 3000-5000 lumen then without mod, under 75$?
What do you mean by “the best”? The brightest? Throwiest/floodiest? Best quality?
The most aladeen.
I posted a similar question Here member 18sixfifty is working on a review for a flashlight in stock form is 7000 lumens and it is $79. I am going to wait for his review and decide between the supfire m6 and this 7000 lumen mystery light.
Took me a while, but I finally found the thread again.
Might have some luck with one of these.
That was a great link. Thanks! More to think about.
I saw this one:
But I don’t like the battery types.
I would go for a supfire m6, the srk style lights are bright and have nice form factor. 4x18650 give long enough runtime.
+1 on the Supfire M6 train, especially with the mod.
I gave one to my uncle who lives in the middle of nowhere, Pennsylvania, along with four batteries and a charger, as a new years present. They get power outages quite often, and once he showed me what lights he is using, well, it felt wrong that he didn't have at least one decent light.
Anyway... fast forward to about a month back, asked him how he liked the light. He had a complaint... said it was too bright :D
There's nothing wrong with the battery types. Use the adapter tubes so you can use 18650's