In short, what is your son's perfect world? For my oldest son it was about using his baseball skills as leverage to get into a high academic school with the best engineering program. My son selected from high academic D1 and D3 offers based on their engineering program. He made it very easy in that regard. There are always going to be athletic, academic and financial considerations in any recruiting decision. You have to decide what is most important to you and your son.
We didn't have a money tree growing in the back yard, so FA was a huge factor in our decision. We found two Ivys to have very generous Financial Aid. He wasn't necessarily interested in a professional baseball career and he knew this ahead of time. He loves baseball and wanted to play in college. That is it in a nutshell.
So, in our situation a PG year would not have been an option or even a consideration. The incremental investment in a PG year was not going to yield a far greater situation a year later for us. We never considered it. Your mileage may vary. I agree with TwoBoys that a PG year is not the answer for an unsuccessful recruiting journey. Your son has high academic options, I wouldn't make this more complicated than it needs to be.