Doubt about sqps

hello.i I am in 10th rn. I am just learning from ncert and educart question bank for all subjects ..doing exemplar for maths too. Near boards..I planned to do some pyqs too

But my class teacher is saying we need to buy a "past 10 years solved sample papers" and solve it too.

I went to shop.and Oswald edition was there and it coated 800 rupees! Which is very expensive. So do I really to do them or is my teacher spewing nonsense?