I've been to the Dortmund vs Schalke game and I think we bought off touts if I remember right.
I was quite disappointed if I'm honest given all the fuss about Dortmund fans etc.

It was their big derby and I expected more. It had a bit of a tourist feel about it similar to El Classico.

We also went to watch Eintracht Frankfurt vs Gladbach and I preferred that much more. Felt more authentic.

I recommend Turkey though. Off the scale