I feel like this claim needs support.

All of the studies I'm aware of that ask people to choose between different price points based on privacy end up showing minimal valuing of privacy.

It is clear that many people know that many services they enjoy compromise their privacy. These stories have been covered by mainstream media ad nauseam. Jokes about privacy compromises are part of pop-culture at this point.

Most people, however, are not enthusiasts or activists who are wholly invested in these topics. Even being aware of the issue, most act based on their immediate needs. Immediacy is an extremely important factor in decision-making.

If we were to give this a utilitarian assessment formula:

[severity of problem] * [immediacy of problem] <||> [importance of need] * [immediacy of need]

Many people using social media to communicate with their family may evaluate that as:

[100] * [1] < [100] * [100]

GP's claims and the studies you mention are about two different things. GP claimed that users aren't generally aware of the extent their privacy is violated, and not that they would chose privacy over price if made aware.

Did those studies gave the big picture about privacy?

Why is it that people working in the field tend to be paranoid about privacy, and people outside are not? It can't be that we are just on average more paranoid. It's more likely that we know exactly how this data can be aggregated, stored forever, analysed in the future with capabilities that don't exist yet, etc. I think most people don't understand privacy in those terms.

Counterpoint: all purchasing sites I used so far are tracking me (or at least try to). I am tracked although I pay for the site.

You have to factor in the fact that people know they are tracked whether they are paying or not. Given that fact I'd prefer not paying as well.

There's a difference between valuing privacy and being willing to pay an extortion fee.