As much as people are willing to give!
Backers determine the amounts they are willing to give and are able to continue giving EVEN after the project goal is met.
The point is this - if you are raising $10,000.00 for 10 people to get funding to go to college in India - yet you raise $12,000.00 - the idea is that you would either send another 2 people to college or better equip the 10 you are sending with the extra funds.
In the same example though - if you only raise $7,000.00, the backers will expect that you use that money to send 7 of them to college.
You are able to fundraise any amount - as long as the money honors God and honors others.