Started this game before patch 1.07/1.08 and the game was severely grindy. Not broken but definitely overwhelming on race reward vs car and upgrade pricing. This franchise prizes itself on racing realism then the race purse winnings should reflect that. Here is a breakdown of what the real winnings should reflect.
Indianapolis 500 – Indy Car
First place winnings: $2.5 million
Daytona 500 – NASCAR
First place winnings: $1.5 million
Knoxville Nationals - Sprint Car
First place winnings: $150,000
And so on. The $30k to $70 per race is highly inaccurate.