Auto-translated
Well, right now, all long-term investments are definitely only for unlimited formats. So, I don't even worry about rotation. I crafted a full set for a Death Knight Paladin deck, played it for a month, and now I don't even have that deck in my list. But I think it was worth it; the deck made me happy for a month, and maybe it will make me happy again. I have quite a few Legendaries in my collection that I crafted just to try out and play with; some of them I dust after a while, but I take it calmly – I tried it, didn't like it, and that's it.
Not on an epic or ridiculous scale, though, but still. So, my pool of Legendaries is slowly dwindling, and I'm very happy that I finally got around to crafting Fortuneteller for unlimited. Maybe someday I'll leave rotation altogether if it becomes too expensive.