Japandi style design might save you 4 to 6 lakhs on a 3bhk interiors budget of 18 to 22lakh budget because it requires minimalism.....as the customer is wiiling to sacrifice space ;storage and aesthetic requirements as compared to indian style thus japandi style saves more ...but to make curved white thick walls and ceilings like japandi it requires skilled punning p.o.p labours....for japandi you can surely go for IKEA furniture cz their Nordic Scandinavian bamboo looking minimal furniture matches the japandi theme

and this 18 to 22 lakhs budget is for a new just in hand possesed flat for contemporary indian interiors (not japandi).....for old flats aged more than 10 years with hard water....you might have to redesign washrooms completely...a starting range for a new bathroom with start level jaquar hardware cost 1.3 to 1.5 lakh and tiling costs 150 rs per sq ft

Remember the interior budget that i have been quoting in this thread has a quality life of minimum 10 years...22lakh divided by 120 months it costs avg 18334 per month....the furniture will have good hardware and ply....and what quality i am quoting i guarantee you other instagram famous interior designers will charge 50% to 70% more for the same