I haven't had any problems pulling legendary and such from tier 3 & 4. On a similar thread to this a dev said yesterday that there is a >1% chance to pull legendary on a tier 1 and that their is a difference between the tiers. After they get the critical problems fixed im hoping they will release more data about this or at least change the descriptions so they are not as vague.
I'm damn sure of it, I got one for free and got a beautiful purple (2nd best rarity) shotgun I still haven't put down (and I hate shotguns), then I bought a 4 and got beautiful purple and blue items again. Bought a 2 and completely regretted that decision...they were both terrible green (uncommon but honestly shouldn't have been) weapons.
Not speaking of the whole no legendary below 3 and 4...this is not true.
Just because they all say X items of uncommon quality or rarer does not mean that they have equal chances for each grade of loot.
Random luck will let some people find very rare items in tier 2 boxes, but that's not a good reason to jump to the assumption that tier 2 are just as good as the other tiers, let alone much cheaper to get.
Buy 100 of each tier of box and record the results - then you have a decent start to compare the chances of each grade of item.
I bought maybe 15 tier 2 boxes with resources, and 1 tier 4 with resources. always got blues from tier 2, i got 1 purp and 1 orange in my single tier 4. im thinking chances are better in tier 4 for higher quality items.
I also got an orange shotgun from a tier 2 box, was the first one I purchased too.
Mankind's greatest weakness, and greatest strength, hope.
Regards HexCaliber.