A) Because NASA are not funded to the same degree as they were in the sixties, not even taking into account inflation NASA has a budget less than the cost of the moon landings. You would have to increase the NASA budget tenfold to get to the sort of money they need to get to the moon. The cost in the sixties for the moon landing was $25Billion, NASAs entire budget this year was $18Billion.
B) Because it is a matter of public record that NASA is not funded to the same degree and hence is the sort of question that you could find the answer to yourself given a computer and five minutes.
In engineering you have three criteria cheap, accurate and on-time. You get to pick two so if you want it cheap and you don't want it to go wrong then it is going to take time.
Re-posted as the OP seems to have missed my answer to his/her question.