They give a lot of characters/vbucks away for free. I have a whole list of skins (including the 3 you mentioned) and have never spent any actual money on fortnite.

I can't deny they've made a crazy amount of money from convincing teenage boys that it's cool to buy outfits and play virtual dress-up. But compared to the must-have items of my youth at least you aren't excluded if you have no money.