@randahl I made a complaint a couple of years ago.
"the view of the DPC is that not being forced to part with personal data in order to avail of XXX products or services nor is the XXX card a barrier to avail of products.

"The Handbook on European Data Protection Law" (page 145) touches on the scenario that you have raised as below:

are not serious enough to prevent the data subject’s free choice (provided price reduction small enough not to affect free choice).

https://fra.europa.eu/en/publication/2018/handbook-european-data-protection-law-2018-edition