1. I assume that you don't want to stay in anything less than a five star or four star deluxe.
The cost for such a basic room on twin sharing basis will be like 20-30k per night during 30-1st and about 15-20k during the few days around that time.
If you go for a top tier five star you will spend 40k+ and if you go for a three star you will probably spend at least 10k per night on twin sharing basis.
Assuming you are charged 20k per night per twin sharing basis, you end up spending 120k just on your rooms for 4 people for 3 days.
Frankly, anything less than a decent four star isn't worth it and that will cost at least 12-18k per night on twin sharing basis during that time.
So let us say about 1lac or so on your stay.
2. New Year Party: You would like to go for a five star, and with drinks you will end up spending 30-50k on New Year's.
3. Assuming that you spend 2k per day per person on food on average, sometimes a good restaurant and sometimes a dhaba. That means another 20-30k or so.
4. The remaining 20-30k on your air travel.
5. Assuming you do 0 shopping and all, just to have a decent time you need to shell out close to 2 lacs. For a splendid time, I would say 3+ lacs.
NOW, GOA DURING OFF SEASON
1. Rooms = 2, Rs.10k per night for 4, 3 days, Rs.30k
2. Travel = 30k
3. Food = 20-30k
Extras = 10k
At most one lac for 4 people all inclusive.
During super peak season, the rates are nearly three times overall and close to 4-5 times only for the stay.
Now if you want to stay in a guest house or some crappy place and eat only from roadside vendors, travel by auto and all then it is different.
But if I were you, I wouldn't want to travel by anything less than Air Economy Kingfisher/Jet/Biz GoAir/First Class Train, preferably stay in a five star and have most meals in five stars or top restaurants and travel by taxi. So with that the expenses will obviously be tenfold more.