Vegeta prince of all Saiyans? or King?

[Craddle]

Hmm, I wonder if Piccolo is a prince too...

I am Piccolo, Prince of the Namekians!

- of Demons actually,since his father called himself a king and so did he in the beginning. But that title is mostly self-proclaimed though and the demon heritage lost pretty much all meaning when he was established to be a namekian.

Well, after he merged with Kami, would he still be considered a demon? Even though at that point they were, as you said, established as Namekains. I guess if he were to call him self Piccolo, Prince of Demons, he wouldn't just change it.

[Michsi]

Well, as I said, it was mostly self proclaimed anyway. But after he merged with Kami, Piccolo straight up tells Cell that he is not the demon king so if he threw away that title he would do the same with every other demon related thing about himself. Who knows, maybe it was a clause that Kami demanded

[Fox666]

Hmm, I wonder if Piccolo is a prince too...

No, because Vegeta had an official title from his people, Piccolo on the other hand self-proclaimed himself king.

[Michsi]

Hmm, I wonder if Piccolo is a prince too...

No, because Vegeta had an official title from his people, Piccolo on the other hand self-proclaimed himself king.

Then again, wasn't Piccolo officially king for a day. And before he was trapped, didn't he technically rule the world?

[Fox666]

But he wasn't the king anymore in the next day, meaning Ma Junia has no privileges of being a prince or such...

[Michsi]

Theoretically, his father died a king, same as Vegeta's father. Frankly , it's not much different than Vegeta's claim, now that I think about it.

[Eire]

Piccolo just doesn't care. Also King Vegeta was legitimate king of the nation that accepted his superiority, while King Piccolo was self-proclaimed tyrant overthrown very quickly.

[Fox666]

Wasn't Ma Junia born after the death of his father?

[Eire]

Technically posthumous birth was never a problem when it come to succession, as long as the ancestry of the newborn wasn't doubtful.

[Michsi]

Piccolo just doesn't care. Also King Vegeta was legitimate king of the nation that accepted his superiority, while King Piccolo was self-proclaimed tyrant overthrown very quickly.

Well, Piccolo took over earth the same way Vegeta took over planel Plant. Overthrowing the king by force isn't unusual and I'm pretty sure everybody accepted his superiority out of fear of getting killed. If anything, King Piccolo was said to have had an army himself , probably the demons he created.

I'm not saying it isn't mostly self proclaimed, I already said that, but it seems there is more to it than that.

[Piccolo Daimao]

It also conveniently makes it easy to differentiate the Vegetas when writing.

Except that Vegeta's father was never actually named in the manga. He was just referred to as "the King".

Prince means "first" or more eloquently, "most distinguished". It's not a title that specifically ties to certain property, unlike King.

Every time Vegeta calls himself "Prince of the Saiyans", he's literally saying he's the Best/First/Most Distinguished/Most Worthy of the Saiyans.

That doesn't seem to be how it's treated in the manga. Vegeta's father has the official title of "King of the Saiyans", so logically, Vegeta would be the Prince. There's nothing to suggest that he was calling himself "Prince" outside of an official title, as we didn't see any other character consistently dub themselves with special titles like that (apart from Piccolo Daimao).

And, in some instances, Vegeta relates back to his elite status when talking about himself as the Prince. Not to mention him claiming that both he and Goku are Super Saiyans, but as the Prince, he's definitely stronger than him. It wouldn't make that much sense if Vegeta was claiming to be the strongest because...he was the strongest, with any support for it. Of course, it doesn't necessarily make sense for him to be the strongest just because he's the Prince, but it still makes more sense for him to consider himself stronger than Goku because of his specially appointed status.

It's not only Vegeta that calls himself the prince. It's Dodoria too, which lends more support to the fact that Vegeta is the official Saiyan Prince.

Chapter: 257 (DBZ 63), P12.2-3
Context: talking about the destruction of Planet Vegeta
Dodoria: “But Vegeta! You should thank Lord Freeza! Since you, the prince, looked to have genius talent, he purposefully targeted the planet when you weren’t there!”

Chapter: 348 (DBZ 154), P5.1
Vegeta: “There’s no need for us to wait for Kakarot! Maybe you can’t tell, but I’ve become a Super Saiyan. As long as we’re both Super Saiyans, I the prince will definitely be several levels stronger than a guy like him…!”

Chapter: 357 (DBZ 163), P8.3
Context: considering his defeat by the androids
Vegeta: “I-I’m the prince ,the most elite of the Saiyans…Now that I’ve become a Super Saiyan, I should be #1 in the entire universe…Is it because my opponents are androids…Is this my limit?...”

I don't know how you came to the conclusion that it was merely a fancy way of calling himself the strongest when nothing implies that.

[Pokewhiz7]

I always thought it was out of respect for his father.

[Fox666]

Like I mentioned before, the only time Vegeta talks about the king he is not very respectful.

Vegeta: “Chih…! Don’t feel too good about yourself over that [defeating the King]…I already surpassed the king’s power back when I was a kid…!”

[TripleRach]

Prince means "first" or more eloquently, "most distinguished". It's not a title that specifically ties to certain property, unlike King.

The Japanese word for prince (ouji) literally means "child of king."

Also, regarding Piccolo, both of them referred to themselves as Daimaou, as did Toriyama in chapter titles and such. So if they consider themselves the same rank for that, they would probably do the same for the king of the world title.