This is the famous holiest place for which Sylhet is famous for! You would find a sense of peace and tranquility inside your heart when you are inside and in pray but sadly the people has made it a place of big business! There are hundreds of money collection traps - most of which are not even supported by the instruction of Islam. I would suggest just to go there - pray at the graves and in the mosque. Remember, dead ones never need or seek your money. So spend wisely.