Budgeting for repiping has several variables including what pipe will be used to replace the old, the size & shape of house, & drywall repair. Read more here.
The issue with repiping a heritage home is permitting that will likely be required & the extra time required for permitting and inspection. Read more here.
PEX pipe has several advantages over copper pipe. PEX is much cheaper than copper, and it is resistant to corrosion, a big problem in Vancouver. Read more here.