Renovation is a big project for any new home owners.
Some might not do anything at all and just stay with minimum furniture.
Some will go for hiring contractors, and some will go for full ID persons.
Price range depending on what kind of home (condo vs landed, etc), most will easily range from 100k to 300k for mid average designs/fittings/furniture.

PS: I do acknowledge that some do have poor/unexpected financial planning/commitments for not considering/allocating budget for renovation after getting the house keys, but that's not the topic for discussion here.

Tq for all the sifus. Let's make this a constructive discussion.