Not a bug, this is how the Collector's Chest works.

You have 3 choices to get the objects of the chest:

- A random selection will cost 15 $$$.
The random selection is on ALL the objects of the chest, doesn’t matter if you already have the object or not in your inventory. You can get multiple copies of the same object.

- An accurate selection will cost 25 Fee’z.
Selecting this, you can choose the object you want! The best way to quickly obtain your favorite objects.

- The option "Buy all" will let you obtain all the content of the chest at once for 499 Fee’z.
It is the simplest solution to get all the objects!

Closing this topic now.