After opening another premium booster box (I hope I got the name right, the one for 300 crystals) I was awed again by the number of duplicates in just one booster. So I went to cards and counted my duplicates so far (easy for Amoketh).
They need to increase the drop rates on the long term. If you want to stay competetive, you need to get bombs. The pool of cards decreased heavily with the new standard and I get smashed by good Kaladesh cards I don’t own, because I simply had no luck. And I play daily for about 2 hours.
@AngelForge, I have about the same rate as you, 63 cards and another 34 dupes. I didn’t count specifically, but I did find it surprising how many times I’d get one card, then the very next card would be a dupe. Happened 4 or 5 times when I opened my two most recent two premium packs (can’t remember what happened before).
´To have any significance we would need comparative numbers from other sets and look at dupe numbers in different rarities. Anything else comes more down to feeling than actual fact.
I checked and my cards so far are inline with those in the OP. I have 55 unique cards and 28 duplicates, so a one-third duplicate rate sounds about right.