My point is to be really wary of the big money prospects b/c that's where the temptation to play games is highest.
The best bet are lower cost guys who are less physically mature (i.e. normal for their age group) who you can project to fill out.
A good way to think of this is giving huge bonuses to 9th grade kids, outside of a few, rare outliers, you'd be bat crazy to do so. Between 9th and 12th grade, there's a huge reshuffling as kids go through puberty and growth spurts. Even then, how many HS prospects turn down the 3rd to 10th rd bonuses to go to college and blossom, not to mention the guys who would be taken at the end of the draft if they skipped college who become real prospects three years later.
It's hard enough to project 18 year old athletes to 22-23 years old, it's a fool's errand to project 14 year olds.