There are a few people on this forum who seem to enjoy crunching numbers. I see there’s a thread about the total credit cost of every car in the game, etc.
I’d like to see similar about adding up the total value of every event in the game, including the championships. I’m not bothered enough to add it all up myself. But in my opinion, what’s required to get all the cars is to just play through the entire SP campaign several times over, with a few time trails and circuit experiences etc thrown in here and there, along with roulettes and the new weekly challenges. You’ve just got to manage your money carefully and keep an eye on rotations - if you can’t get something this time you can plan for when it comes round next time. All that.
That’s how I’m playing anyway and i’ve never felt the need to run the same track over and over. There have been 3 very high value cars in the LCD this week, I’ve accepted that I won’t be able to get all of them. But the Ferrari is on a faster rotation than the others, and I already have a Porsche racecar so I’ll get just the F1 this time and wait for the others to come up next time, or the time after. In the meantime I should be able to afford some of the cheaper cars and whatever (if any) I get invites for.