I don't understand that perspective. On the one hand, they are confident enough in his talent to think that two years will put in the first round. On the other hand, it seems like they are not confident enough to value two years of movement through the system since first round talent should advance relatively quickly (if those two years put him closer to the majors, even an extra season at the major league minimum gets him $500,000)
Well, at 18, let's say it reasonably takes him five years to get to the major league level, starting out at the 800,000 bonus level, let's be generous and say the Nats can squeeze an extra $400k and get him up to 1.2 mil.
If he thinks, as I would expect someone of his talent level would, that with three years of learning under a guy like Erstad, whom he really has a pretty good relationship with already, that he can move up to a top 20 pick and could get to the MLB level in, say three years, at age 24 after signing a bonus of better than $2 mil, minimum, it's not really that hard to follow that logic, to me. There's some risk there, no question, but the logic makes sense, I think.