Many of the plants mentioned in this story are no longer rare or expensive, depending on how easy they are to propagate.
For example, the article mentions a “Pink Princess” Philodendron. These are not difficult to grow, but the pink variegation is notoriously unstable. In 2019 I sold a small one of these plants for $125. Today you can buy a similar plant for $20-40 on Etsy from a reputable US seller.