I know this sucks that you can't do this but it's not the end of the world.
This is NOT required for 100% so if that is your goal-- don't sweat this.
I know there is a trophy/achievement for this but the cost of the business is $200,000
Franklins payout for the Jewelry heist should be in the neighborhood of $300,000
So if you want to start a new game and purchase this then you only have to play up to the jewelry heist to have enough money-- on my game this was only about the 12th mission or so. Of course you don't get paid right away so you will also have to complete 5 Trevor missions before you can play as Frankin again.
Forgive me if you have to play farther into the game to unlock the ability to purchase businesses.
My point is-- you can still get the trophy without replaying the entire game.