has a water tank leaks, car runs without water, now not start, only make noise re..re... what to do

Hi we have a Holden Barina 1995 with water tank leaks, my son runs the car without water so it stops, it makes noise re.. re...but don't start.
A mechanic quotes $1500 to replace cilinder head gas get, water pump; timing belt; radiator, themostate, oil and filter. I feel this is quite a lot. What is your advice? Thanks