Forza Horizon Coins MMOGA?

I bought an Xbox One S recently.

Of course, as a car fan I have to play Forza Horizon and I do not want to start with 0.

Now I have MMOGA for eg 5 Euro = 20 million coins

A colleague said I have to sell cars, which are then bought extremely overpriced.

Can it be that you just get the money written normally?

(As if you buy it ingame)

So in fh4 there's no ingame shop! Would be better, otherwise the topic pay2win occurs again.
As far as I know, there's a possibility to sell cars up to 20 million. Depends on how good your tuning and designs are on the car and how often the car is on offer