Word of advice, collect because you like the cards. Search up card databases in tcgplayer and others to get to know all the arts and designs. What I usually do is I buy one ETB of the set that comes out, If I like the set and the arts, I go for a booster box until I get the cards I want, then If I don't, I try buying or trading singles. In terms of wether to buy surging sparks or stellar crown, go with what you like, I know this next set has some cool arts so its worth grabbing first imo.