Plenty of teachers buy classroom supplies with their own money. Those markers have a backstory.

Some of what gets handed to you was bought by someone out of their own pocket, quietly, with no system paying them back. That spending arrives without a label, so it reads as ordinary supply. Behind a lot of plain classroom stuff is a person who decided the gap was theirs to cover. Knowing that changes how the room looks.

Ask a teacher sometime this week where something in the room came from. If the answer turns out to be their own money, say thank you plainly and treat the thing carefully. That is most of what anyone wants for it.