???? Dude this is for Br style racing...
[added 3 minutes later]
I found something so simple, I feel dumb for overlooking this. Instead of changing the values, just freeze your values and buy whatever you want, then when you're done un-freeze them. The game still works after that. I'm not sure on his much you could increase the cash though because I changed my cash to 50k and the game wouldn't open. Changed my cash to 2100 and the game did open... So there is a cash limit somewhere. But if you have enough money to buy things, just not enough total money to buy multiple items, just freeze your cash. Then buy all those items, then unfreeze your cash. Then you can exit and re-enter and no problem, game works like a charm.