Warrior -
Time to start doing some research bud.
Couple of points to mention.
Grades pay. Big time!
Many of the D3 (note: I said "many" not "all") programs happen to be private colleges which happen to be much more expensive than public colleges.
Sometimes that scares off prospects because D3's offer no athletic scholarships.
But as a mentioned already, grades pay. These expensive private schools are competing with inexpensive public schools by offering lots of academic scholarships.
So be sure to keep grades high!
Since you're from New England, you are probably familiar with more D3's than you even realize. Check out the D3baseball.com link.
Down here in Virginia D3 baseball is awesome. Great schools, fantastic facilities, very competitive baseball. About half the schools on the VA College Bus Tour are D3's.
Good luck.
Rich