I have one tree, not sure if it is grafted or seed.. have to take a closer look. Spent quite a bit on it here, above average for nursery trees. In Thailand it is marketed as "Lamyai Crystal" -- ลำไยคริสตัล more than plenty on the market now. Lamyai = Longan.
It seems to be doing fairly well with the weather and rain at my place, in potting soil now, mix of cow manure, coconut husk, composted chicken manure and rice hulls, and crushed rock.