If you have a good idea of what you want it is well worth getting round a few places and getting quotes.
Our kitchen was about half the price of the highest quote and made by a speciallist kitchen maker so has various individual features that Mitre 10 just couldn't cope with (it was about 30% cheaper than the Mitre 10 quote and they got some things wrong)
Another option is to get the standard cabinets in a flatpack like Mitre 10 or Bunnings and get a cabinetmaker to build you the ones that aren't standard size - the basics of construction are similar and the colours are easy to match.
Well I caint say nothing apart from ditto to what Wino just said. The price we have gotten from a joinery place is less than the flat pack at Mitre 10 and half the price of another kitchen manufacturer.
that is interesting re the Mitre 10 pricing, we were set on a flat pack from them before reading your posts, and having ran the same plan by another Franklin Kitchen company who swore they couldn't match it at all, I was set to settle for the M10 one....