I have quite a few tropical trees i have grown from seed or propagated from a cutting. Jacarandas, Tamarind, montezuma cypress, Palo Verde just to name a few. These are trees that I keep in a heated greenhouse in the winter, although they could work well in a well lit indoor space. I grow them with the intention of bonsai stock. They could be used for that purpose or grown in larger planter indoor or an office setting with good natural light. I have not sold any of my trees before so cost would be figured out in a case by case basis. I think a range of $25 for small trees and $100 for the largest is a starting point. I am mainly testing out the interest to see if anyone else other than me values these tropical trees, or bonsai starter stock. As of now I simply have too many trees.