how much is it to replace a zip?

[Nagoo]

On a pair of jeans.

I've only had my Kristen jeans for a couple of months and I have broken the zip :(

A local dress maker charged £4.50 incl new zip. Was very nicely done.

I would take them back and complain about the zip breaking so quickly. Hopefully they will replace them. It is quite expensive to get zips replaced.

I don't have a Topshop near me. I got them online. I figured it would cost as much in postage and bother as to get it fixed.