What makes a plant "rare"?
Rarity usually comes down to slow propagation, not biology. Variegated plants like the Thai Constellation cannot be grown from seed and multiply slowly by tissue culture and cuttings, so supply stays behind demand. As labs scale up, yesterday’s rare plant often becomes tomorrow’s common one.
Are collector plants harder to care for?
Sometimes, but not always. Variegated plants need more light (their pale sections cannot photosynthesise) and grow slower; velvet-leaved aroids want higher humidity. But many collector plants are simply ordinary-care plants that happen to be uncommon — check the quick-facts card for each.