There is no reason to even limit this at merely Cards. In future, I'm open to having Titles, Skins etc. bought through VOUCHERs. What I am frustrated with is the lack of choice with the use of VOUCHERs. Mana Warden was an okay Card and recently it was taken out of the shop.
I did not have enough Cards or VOUCHERs to reach Level 3. I had to make some sales and Level Up the Card. The current supply of Mana Warden is very low compared to many other Common Cards (especially form Chaos Legion).
Ulfga The Blighted is For Whales
I have staked 126,913 SPS and I am still not sure if I would be able to purchase 1 of these Legendary Promo Cards with what I earn in VOUCHERs. The Card will only be available for 81 more days. Ulfga The Blighted seems to be a good Monster to have in the Deck. It is not accessible for most players. Many will simply sell their VOUCHERs.