I keep reading about users having tried the Random boxes only to then post when they have won nothing.
They think 1% so 100 boxes will give me the item and 50 will give me a very good chance (50%).

so here hopefully is something that will help you think twice about it.

So you want to win something out of the random boxes and you think that as its a 1% chance of a win I could buy 20-30 boxes and have a really good chance.

To show the problem with this logic, let's imagine that you buy 3 boxes. What's the probability you get at least one perm weapon? .

The correct way to attack this problem is to understand that "winning" is equivalent to "not winning".

In your case, you have a 99/100 chance of not getting your item.
The chance of not getting your item three times in a row is (99100)3=970279/1000000.
We're looking for the probability that not getting your item three times in a row doesn't occur, so our final answer is 1−970279/1000000=297011000000 = 0.03.

The problem for most is that they think the more boxes they buy gives them a much greater chance but it does not matter how many boxes you buy the chance for each and every box is still only 1% and gold is only 0.1% but that depends on the 1% win in the first place,

Basically if you want to try the Boxes be prepared to come away with nothing and only spend what you can afford to, if you do get anything then its a bonus.

Remember this is gambling and unlike a lot of other forms there are no fixed payouts here so the more you spend will not really improve your chances of winning
more likely to make you miserable than anything else.

And posted by Levak the below will explain more

Gold weapons in Random boxes explained
Hello everyone,

I'll put an end to some spurious rumors regarding Random boxes and Gold drop changes.
Gold drop chance is 0.1%, (normal version is 1%) but knowing this is rather useless. You are either lucky or unlucky...
Even if you know you have 99% chance for a gold, it may still make you rage, perhaps even more...

Here, I will be talking more about one aspect of the Random box mechanic that I find _should_ have been told to us, players.
The reason for this, is that we should know the maximum price we can put into a random box before giving up. Maybe it's the next box? maybe in 2? We get dizzy and fed up by the time of thinking it.

Win limit parameter

Every random box that may deliver a gold item have a parameter called "gold win limit". This laddies and gentleman, stands for the maximum number of boxes you will have to buy before dropping a gold.
Reached that amount, the gold is _for sure_ going to drop, what ever your luck, you will have it.

Sounds exiting? Eh? Not that much.
On most (if not all) random boxes, the win limit is setup to 1000. Since most of these boxes are for 2700 WFD, this means the maximum price for a gold weapon is :
2.700.000 WFD if you buy boxes 1 per 1
2.540.000 WFD if you buy boxes 5 per 5

Win limit counter

Every random box holds an internal counter. This counter is unique to your profile. Every time you buy a box A, you will raise the counter for A only. If you buy a box B it will count for the B counter. These counters are stored inside your character profile, so you won't have more or less chance by staying in the box display shop or by quitting the game. That way you can buy one box every day and increment that counter.

Finally, every time a gold drops for a particular randombox, the internal counter resets to 0.

FAQ

Is there any tactic?
Nope, neither for the gold or the normal version. Just pure RNG.
Random box drop chances are neither (directly) linked to the number of players, nor to the time you spend in the safe house, nor the yadi yada you perform in front of your computer. You'll get either lucky or ultra unlucky.

What if I already have a gold and keep spending?
The drops from the random boxes are affected by no other values but their own weights (drop probabilities). This means it doesn't look into your inventory to see if you already have a gold version. You may drop multiple times a gold version, which will reset the win limit counter every time, even if you already have one. Please note that gold weapons do not stack. So, think twice before continuing spending on a box where you already have the gold version. You may rage _a lot_ seeing another gold drop while you could have sold it on auction house before....

The boxes rotated, did I lose all my progress?
Thankfully, no. Box counters are individual items in your inventory. They don't reset unless you reach the 1000 threshold. Figure it as a consumable. You accumulate them and once you reach 1000 you are "eligible" for the gold price for that particular box, even though it's done in an automatic way.

I SPENT OVER 3 MILLIONS AND NOTHING WTF R U SYNG
You just miscalculated. 2.5 mil is close to 3 mil, just keep trying.
You can also count up to 1000, but that will be hard to track by "hand" :^).