Hi Mahesh,
After the basic structure is done you can save in every item ,if you are supplying material to the labour contractor .
Flooring -
Vitrified you have range of variety from 40/- to 200/- per sft ,granite you have range from 80/- to 400/- per sft, marble from 50/- to 600/- per sft.
Decide the kind of flooring depending up on hierarchy of spaces , don't spend for looks in functional area like utility,kitchen,store rooms,guest bedroom etc.....
Plumbing -
First thing you should understand that any premium range in taps need pressure system to work.so when you pick any tap or shower check with vendor for the pressure required.Pressure pump is an extra cost implication.
Go with maintenance free and decent brand like jaquar.
Interiors -
You can save a lot if you are clear about it,all the wardrobes internal partitionsons can be done in concrete itself called as andhra slabs.They put internal supports with concrete slabs of just 19mm thick .This saves a lot money in interiors .Also if you do other counters like tv unit ,buffet counter,wash basin area you can save a lot.
For tv ,buffet counter you can clad with veneer or laminate later .
regards
Ar.Praveen.N
Ardes Archtiects and Interior Designers
ardesarchitects@yahoo.co.in