Making useable decks without buying singles?

I know that the general advice in any TCG is always just buy singles when building decks, but I just have a general dislike for getting cards second hand. There is something about knowing I pulled the cards myself and using what I do have to fill holes or make strategies that makes TCGs feel more fun and personal to me. That said is there any sets or directions I can aim/focus on as someone just starting in the Digimon tcg for that allow for usable decks, not necessarily high tier ones.

So far ive gotten 3 starter decks:

Hero of Hope and Protector of Light (mixed together for one deck that seems fun)

Along with The Data Squad deck

I really like the Shambala digimon but am unsure if its worth jumping straight into that set or if it needs a lot of support from older ones.