As usual, great stuff in this thread. I'll add something my son and I laughed about from this past AFL season. He rented a house with 6, 2015 guys from the Atlanta area. He, along with his college roommate were the only two who went to college instead of the draft. His roommate had much more of a chance to take the money and run after HS but went to college......my son didnt have many options for the draft but regardless, as they began their cohabitation with the other guys.....conversations popped up about college and what it was like as the other 4 guys have been in the minors. It was at that time that my son realized how much he missed college, his teammates and had the thoughts of "If i could go back etc". He said him and his buddy felt like the "old Men" in the house.
Regarding your initial question, i would go to the scout days and network. They know the deal and although many scouts could be around in 3 years, many move on. Low level guys don't lead a glorious life and usually travel quite a bit. Whatever 'life changing" money is for you or the amount that moves the needle in order to be drafted vs college should be discussed and if you do not get it, go to college. Obviously the college opportunity you get could play a factor. There is always the Juco route as an expedited was to pro ball. Everyone is different, some have plenty of college money saved up, others need to help support their families...and everybody else is in the middle.
I know my son benefited greatly from his experience and we have talked on more than one occasion about how gracious he was with his HC at that last Clemson v Vanderbilt game in the regional when he knew he wasn't coming back.