If you want money then playing online is possibly the best way to make really good GT5 money and have fun at the same time.
Online game play is not only awesome but the rewards are spectacular. Most wins will net you $50,000 or more even if there are only 2 cars on the track. Play 1 hour online and you’ll make as much money as playing a whole day of non-networked play. Plus, it’s just more fun. No brainer here!