Beggars can't be choosers.
If a person doesn't have the means to provide himself with something better, he should accept with gratitude whatever he is given. He has no right to complain.
Beauty is only skin deep, but goodness goes to the bone. External beauty is only a superficial quality and it may hide an unpleasant nature. Goodness on the other hand is very deep.
A diamond with a flaw is better than a common stone that is perfect.
A rare, precious opportunity that comes with some problems is better than a regular opportunity that seems to be perfect.