digital piano or midi controller with samples?

A MIDI controller would mean having on stage: controller - PC - audio interface!

In my opinion, a digital piano is better, not to mention that it can itself become a MIDI controller; perhaps with fewer knobs, but still capable of making its mark.

It depends on you... In the case of samples, you have greater versatility. You can choose from many classes that more or less adapt to a musical style. This way, you have the possibility of choosing the piano that best suits a particular event (but it becomes something for real perfectionists). As Mica says, for live performance, it might be advisable to go with a digital piano. You can still always interface it via a MIDI interface with a bit of [effort] and exploit all the libraries you want. In the case of the digital piano, the thing becomes reversible and 100% usable. It is true that you have a few fewer knobs, but you can still map your keyboard keys if they send MIDI data to a sampler and use them as you see fit with the learn functions. These are the possibilities; now choose the one that is most suitable for you.

Well, the fact is that by buying a midi controller instead of a digital piano I would save a lot of money....anyway, I'll think about it, thanks

Well, I wouldn't say that... Consider that a basic 88-key MIDI controller costs around 300 euros. Look at the Logic SL990 studio, for example; if you go for an analogous digital piano, like the Casio CDP120, you're looking at around 350. In short, I don't think it's those 50 euros that make the difference when you have to end up spending money and you do the same things as that controller. I would think about it for a moment...