I don't see how it's a steal, but it probably and unfortunately is, DeRozan's market value.
Ntilikina is one of the worst offensive players in the league, but at going on 22, with superior physical tools (6'-5'' 197 7'-0'') to defend 1-3, if he ever becomes so much as a credible spot up 3-point shooter, he could become a valuable role player on a good team. If not, he probably becomes Carter-Williams.
I'm not really interested in him, but he'd open up more possibilities. Either re-route him for an early 2nd in '20 or '21 or retain him and it becomes easier to trade White.