need some advice

This question is about money. I am having a small problem.

In addition to seo, I also do translation work. Being a translator is not my main job, I only do it sometimes.

I am in USA. I was contacted by this hotel who said they have a guest who speaks my language. He speaks zero English.

I got to the hotel and he said he really appreciates that they found me because he has been desperately looking for a translator etc. etc.

It turns out that the guy is loaded. He is in the real estate business and he spends money like it's nothing. He literally told me if he and his children never work, they will never run out of money.

The problem is, we never discussed price. In my culture, it is disrespectful to discuss price, especially if you are younger and the guy is older (this was the case)

How is price determined? it is understood that the price will be "reasonable." so for example you ask your accountant to do your taxes, and never discuss price. When it's done, he will say $300 and you say "$250" and he says ok. This is our culture.
so I was with him 7 hours today and I am supposed to see him tomorrow.

I thought maybe at the end of today he would offer to pay, but he didn't.

I am afraid he believes I am doing this as a favor. Tomorrow, how can I make sure he doesn't believe I am doing this service for free?

Hi, maybe he will be paying when you are both done with the translation. However, I think, you need to discuss or pitch a topic that will lead to an agreement about your task. You may start by telling stories about your other clients and how they offer you something out of your job as a translator. I guess, you should be honest also to tell him about your rate for a certain job