gold status would get you & another family member to the lounge....you will be able to check-in all family members at the gold/plat counter....
i don't believe there are any hidden costs with the package deals....
also note that for 2 return redemption tickets with jet you will end up paying about inr 12k in taxes....add the inr 30k for the 2 other tickets....then you will have to pay for your hotel room seperately....if you have a 5 day stay at a low-mid range hotel then you pay about 20k....
with this is mind the kingfisher deal sounds like it will end up costing you a little less....