I don't think that players make $1,500/mo until AA. I think starting salaries are around $1,200/mo or even less.
So, $1,200 less FICA and Medicare and other state fees (e.g., disability) leaves around $1050. Subtract $350 for rent (host family; an arms length apartment is far more and carries some form of lease), $150 for club house dues, add $350 for road per diem and a player has $900 for the month. The player will pay for roughly 60 meals per month himself. Assume $8/meal (great high quality protein cannot be purchased for that; but a steady diet of Big Macs can) leaves roughly $420. From that $420, the player pays gas, insurance, etc. - $15/day for everything beyond room and food.
Now, you can insist that your player doesnt need the post-game beer (to come down from the during-game chew) and can live on air and love for the game alone; but, that player is the exception not the rule.
And the player is also required - required mind you - to file a state income tax return in EVERY single state he player. Try finding an accountant to do that for some small sum - so it's mom and dad on the phone with multiple state tax entities trying to navigate the maze.
On top of that, the player's cost in the off-season skyrockets as he is contractually required to remain in first class physical condition, must take his skill lessons, live somewhere (mom/dad - so long as the town has the personal coaches needed), eat, pay for the car, insurance, cell phone, etc.. Of course, the player can work around his 4 - 6 hours a day needed for baseball - but the jobs available are limited (coaching, manual labor).
A player living in an apartment is far worse off financially.
Also, while most employers look upon the baseball experience positively, the technical skills the player had during college (e.g., the ability to be fluent in EXCEL) all but disappear in several years in all areas except baseball.
IMO, chase the dream with your eyes wide open. Pursue the dream - but realize it's a dream and position yourself accordingly (good college grades, good college major, max MLB scholarship money possible (for those who get it), network for the future in college). For parents, recognize how much you are willing to subsidize the dream (a pro athlete can eat a lot of good protein, needs a car to get to work and play and gas and insurance, a phone, showers a lot, needs to join a work out facility, pay for lessons, etc.) and has a limited ability to bring in income.
For us, except for college tuition, his living expense INCREASED when compared to college.