Refurbish old Myvi will cost just a fraction of buying a new one.
I own a 2010 Myvi and after close to 10 years, I've changed quite a number of parts. The parts I'd say are cheap.
Changing common wear and tear parts, respray I think will be in the range of 5-7k. Buying the car will depend on which year and version of Myvi you get.

Yes, as good as new.
Of course you need to know what to change and buy the parts yourself from spare part shop and get workshops to install them for you.
It will be cheaper this way and you can be sure you are using genuine parts.
If you leave it entirely to a workshop, price should be higher.

You can do it one at a time like fix the absorbers, lower arms, suspension link etc and brake system first.
Then go with engine mountings, beltings, fluids.
Then go with the car body paint, rubbers door seals or latches as body shops can do these.