Reason 6 not to pay "free to play" games: Failure to disclose probability of items

WOW!  You see an item in the game shop that you want to buy.  The only way you can load up with this item is to buy it with in-game currency that you only can purchase with money (such as US dollars or the euro).  After you bought a few of these items, the description says:

Open this chest to receive one of the following items:
Gold x XXXX
daru x XXXX
gem X 1
crystal x 1
Nice useful item x 1
Nice useful item x 1
Useful item x 1
Extremely useful item x 1

Here is an example of one of these chests in wartune:

You open the "Clown Chest III" to receive one of the four items.  When I opened this Clown Chest it seemed that each of the items listed was a 1 in 4 chance of getting it.  What about the other chests?  I see there are 10 possible items to get in the 2nd chest.  So you would think by opening the chest 10 times you would have gotten all of the items?

Actually, it is not the case.  Wartune does not disclose any odd's of any of the item in any of their chests when you open it.  Many blogs calculate probabilities by asking people to send in what they got when they opened up chests.  Shouldn't that be Wartune's job to supply this information and not fan-based blogs?

I look at it this way.... when you buy scratch off or a lottery ticket, they will display the odds of each of the prizes you get.  Buying a lottery ticket is completely optional.  So is buying these items.  The game at least should be disclosing these items but it's apparent that many people have no interest
 in knowing what the probability of each item is before they buy it.  Not only should they be disclosing the probability of each item, they should also be disclosing confidence interval test validating that their probability formula is working and paying out as claimed otherwise you run risk that you may be scammed.