As stated above this does need to by dynamically adjusted to a fair market value which it currently is not.

Sure it stops older players farming the rewards across multiple accounts but its now a DEC sink that hurts players for using it.

Cost is 750 DEC so 150 DEC per chest.
Estimated value of chest (from splintercards) is 108

Or 750 v 540 for all 5 chests from each potion.

So your effectively burning DEC every time you use this - gambling you might hit a good card but with a negative EV nobody should be doing this.