So what I've learned from the my best experiences in roleplaying is that grinding is generally bad and fruitless. It's neither realistic nor fun to grind script jobs so you can buy the stuff you want. Personally for me, the best experience I had, was that acquiring businesses in the first place should be VERY easy. That said, you have to consider that I'm talking about rather normal and small businesses, an electronics shop, a flower shop, a cafe, a bar, etc. These businesses are the heart of roleplay and can be given out to people so that they can start roleplaying at once. Of course a management group of sort should be there to overlook the process, both ICly and OOCly and keep the business owners in check. As for bigger businesses like clubs, casinos, dealerships, and generally the ones that require a large investment, the same management group should give them out by applying more filters and more reasoning for the person who applies for such business. Also another script that I've seen that's worked very well, is that server pays the people who work at most of the businesses by their active playing time inside that business. You RP an hour in a 24/7 when you are hired there and you get X money from the server. This makes roleplaying the best way to acquire money and bypasses many of the grinding ways that have been seen in almost all GTA roleplay servers.
Another thing to keep in mind is that money can be an OOC asset. My character could have 100,000$ in his bank account but I should be able to ignore that and roleplay a homeless person. So I myself am against any sort of limitation that prevents players from roleplaying what they want.
I have a lot to say but I will pour it out gradually since I have no idea where the management here is headed with the script.