Tavern Won't give anything above Blue quality in cards.

[Herby]

And the only you're getting the 5-7 purples is if you're spending gems on top you refreshes.

I never spend gems on shuffles.

[phantommop_569636]

I never spend gems on shuffles.

Yes.. yes you do. Deny it all you want. you either spend gems or are lying about your results.

[Wildflower]

I have had weeks of around 100,000k credits where I did not get more then 1 purple card.
They did pass though, spirits went up nicely.
Today I spend 70,000k credits and, lucky me, got about 7 cards, few purples and few gold ones.

I guess after a dryspell things can change.