I sympathgise with you, all the prices seem astronomical!
We looked at the rooms at the Casa Sea Shell in Candolim and they were fairly small but more than adequate and were priced at 900rps per night (but these were not Xmas prices). Very clean but no a/c.
If it's any use to you here is their e-mail

seashellgoa@hotmail.com
and the contact name is Sameer Shirodkar

I also have phone numbers for Maggies Haven if you want it I can PM to you.
I haven't seen her rooms but they are behind the Stone house restaurant in Candolim and her prices START at £80 per week per double room.
There are also some other suggestions if you read through the various posts on here

del949

I have found the best thing to do whilst you are in goa is to spend a day looking aroud for apartments to rent, we are going to Goa once again in November until February and have hired a villa with cable TV fridge, etc etc and the three monts will cost us 250 pounds, plus the airfares, it is a lot cheaper doing it this way, plus you dont feel as though you have to go out every night as it does get a bit monotonous after a while.