Initially they will tail you that whatever lowest quotes you got from other agencies, they will bit all of them. Since they are having direct contact with travel vendors, they can make it at lesser price. Like that they use to attract customer by saying some lesser price and ask for advance amount. Afterwards near to your journey date, they will say that they can't provide this package in the same price, until you are paying more amount. By that time you will not find any other good option and hotels rate will be in pick, since your journey date is very near. That's their tricks. Same happens with my recent Andaman Trip, and I paid Rs.20,000 in advance. Later they told me to pay extra amount to avail that same package. I denied to them and ask for refund, then they were saying hundred of stories, not responding my call, mail properly. After long time followup somehow I managed to get my money.
If you love your hard earned money, then I would say don't even take any deal with them.