How much have they paid to support yous educations? If they have hardly paid any and neither spent too much time to raise u up, 5k is enough as they also have 30k disposable incomes..
If they ve put lots of money n time to raise u up, then give them 10k n cut all other expenses to minimal..
My case: I took scholarships for all my edu n so I only give enough money to my family to maintain living costs n in case thy ve big things going on, I ll either share with my siblings or bear the costs...