I'm not sure what you mean here. The way the books say it, I think Hogwarts is like a public school. You just need to buy supplies.
True. But when Dumbledore saw Tom Riddle in the orphanage, as seen in the pensieve, he explained that there was a fund for students who needed financial aid to buy books, robes and supplies. He gave eleven year old Tom Riddle a bag of money to shop at Diagon Alley. Riddle was determining to find the place and shop on his own.
Note: The word is scholarship.
If more of you Wiki questioners would read Rowling's exciting, powerful saga, I believe your spelling, sentence structure and word comprehension might also improve.
Dumbledore told Riddle that he would need to purchase some things second hand.