For students, there are several PGs near Amity University in Noida. The majority of the students stay in the PG lane on the opposite side of the road. You will not face any problem in locating one within your budget.
One of my friends is from Amity, and she is staying in Santorini House, a student PG run by Stanza Living.
One more thing that you will find very cool is that they have partnerships with nearby shops and restaurants such as Egg Bistro, Fuels Café, Chao Bella, and others. This enables students to receive significant discounts on food orders.