What's the Name of That Book??? discussion

Must say, I read this book like 4, 5 years ago, but it was in the library, so probably it's a year or two older.

I can't recall a lot, but the main plot is clear in my mind: the main character was almost surely called Sascha or Sasha, something similar; he was a boy that lived in the streets, some kind of antihero, who knew a lot about coin tricks and used to play with them. He was picked up in some carriege, in this fantasy setting, because he was offered the chance (idk how or why) of a new life; but there were other kids, all brought to a mansion, who were competing for that oportunity.
One of them I'm sure was met in the carriage, he was the typical scribe kid: more silent, shy, smart, the companion of the main character., at least at the beginning.
I don't remember how hard the competition was, but all the kids were trying to be the best heirs, not with any blood contest like the Hunger Games or similar, but learning manners, studying, fighting each other... The lord of the house (I think he was?) was a very manipulative guy too.

I'd love to have luck and find this book, thanks if it resonates with you!

Could this be The False Prince by Jennifer A. Neilson

The main character is named Sage and the plot seems similar to your description, I don’t know how to link it though

The False Prince by Jennifer A. Nielsen for Hazel's link