Yes, it's expensive. But if you can afford it, you'd be hard pressed to find a more outstanding place to stay at in Heraklion. The place is just as gorgeous as it is on the pictures. We only stayed two nights but we really didn't want to leave. Chilling in the outdoor jaccuzi with those views - you really need to experience it. Communication with the host was prompt, clear and they were there the minute you needed help. We had an amazing stay and we're dreaming of going back again.
One thing you need to keep in mind is that it's not central - you'll need 20-25 min to walk to the city. However, there are fairly frequent buses available and a taxi to the center will take 4-5EUR. Again, if you can afford it you should experience it.