why does pip feel he cant receive any more money from magwitch? is this an admirable trait of pip?

Pip has a kind heart and his is terrified at the thougt that the poor man will be caught and sentenced to death because of him and he wants to get Magwitch out of the country as soon as possible. Last but not least, that money is dirty in his eyes; to continue to take it would mean to stoop too low.