Wild caught and loaded with problems from the start. Needs a specified diet that will be costly and time consuming to either buy or raise yourself (all insects/inverts). Large size and needing a large cage to be housed properly. The need for very high temps/humidity. While you may be able to keep a sav alive in sub optimal conditions for a few years, he will probably end up just like the huge majority of captive bosc monitors- dead.

Bosc monitors are very specific animals, they require a lot more than people make them out to need. They are probably the most neglected varanid available to the hobby, I'd say far less than 1% ever even break 1-2 years of age. If you are set on monitors, look at ackies. Much more stable captives, more forgiving, and don't require as much as a sav does.