When I first started this game, it was in the middle of the demon tower event. Ended up dropping $10 on a couple of series packs and got an edgar and lieselotte, thought that those packs just gave better cards because of their cost....learned through Army and Witches that is not the case at all (I've prolly spent $100 per series and gotten no 5* T_T ).
As far as spending money, the way I look at it, I play this at work and have already spent so much time with it, the dollar/hour conversion makes it very cheap. Though once Solforge comes out I'll probably drop this or play it considerably less. Looking at it from the perspective of someone who wants to design games for a living, this game is probably great for the developers/publisher but straight up abusive to it's end users. That's most social games like this though sadly :/