That is a difficult question to answer because it depends on many different factors. Labor cost in you geographical area are a factor as do local codes and customs. The best way to get a good job at a good price is to get three different quotes and pick the middle.
Depends what your replacing it with. How many breakers are in it? Does it have an RCD? But your speaking from roughly $50 assuming your doing it yourself.
Between 1500 and 2000. It's expensive to get anyone to touch that in a house that old. i thing this is the true price for circuit breaker box. I bought it.