We have a similar home in a sydney beach suburb. We are in a different position where we have bought ours as a downsized but are just about to restore the old 50s beauty to its former self. We have quotes of around $400000 to gut and change the floor plan which includes 2 bathrooms and a new kitchen and also add internal stairs to the garage and a large deck off the back, lift some ceilings and replace gutters, eaves ect ect ect. Attached are my inspiration boards and what the house looks like now, hopefully in about 4 months I can update you.

The above counter cabinet doors are MDF 2 pack poly with metal mesh inserts and the floor to ceiling cupboard are MDF 2 pack poly with v grooves. Does that make sense?!

@brookegatt, yes this is still classified as a renovation as the floor and some structural walls were restored. If the entire house was demolished then that would be a knock down rebuild.

with previous experience of building and renovating DIY, owner builder, subcontracting and full builder service (and somewhere else to live and no full time jobs or young children to worry about) we decided to use a combination for renovating our 50s double brick with redundant extension over several years...stage 1 consulting council and our builder to determine possibilities, preparation and approval of plans and negotiating finance stage 2 diy internal demolition of bathrooms and kitchen, including professional removal of asbestos, stripping out old wiring, roof insulation, timber trims, doors, wall and ceilings linings, brick chimney, opening new doorways and carefully salvaging floor tiles and sections of old plaster cornice for later patching, stage 3 subcontract carpenter, electrician and plumber to replace some windows, open up new doorways and build internal walls, first fix plumbing and new wiring, selection and purchase of all taps, PC items, doors, handles, windows, cornice, architraves etc and plan and order the new kitchen and all cabinetry stage 4 employed the builder and his team of trades to remove old roof tiles, rebuild the whole roof, add new structural supports, extending a new hip roof over an old extension, new wall cladding, new bathrooms and laundry, patch damaged plaster work, replace the rest of the windows, add new doors and timber trims and stage 5 we organised installation of the new cabinets, painter, tiler, plumber and electrician to install lighting taps etc ...i'm exhausted just thinking about it but we saved money by doing lots of work and subcontracting ourselves but the services of an excellent builder was worth every cent because they have the trades coordinated to arrive in the correct sequence and results happen so much more quickly but taking our time allowed us to pay more attention to details and we were able to salvage and recycle and sell items that a builder doesn't have time to save eg tiles removed from our roof were used on our neighbours' extension and we sold all the old copper wire and windows...look forward to learning what you decide