Happy-
On your home phone front, look into
a few VoIP options in your country (Australia). A couple that floated to my attention from the list are
Ace Communications, which provides a full VoIP service with DID (phone number), and
ClicknCall, an outfit that only handles outgoing VoIP calls and lets you set your caller ID to any phone number you own.
Stay away from bundling services with your ISP. World around, it's always going to cost more than doing VoIP on your own. Also, it'll probably be cheaper to buy your own equipment off of Amazon or Ebay than it will even from the VoIP provider.
For the New Zealand folks-
I found an outfit called
Kiwi VoIP Ltd., that might be worth looking into. They appear to be a choice provider for at least
one outfit that does high-volume hospitality industry services in the area. Take that for what it's worth. You should look into any provider I link and vette for yourself.
Home phone's always going to be cheaper than mobile per minute, and VoIP will always be cheaper than whatever's provided by the phone company or your ISP. Take advantage, and you won't have to spend as much on the expensive mobiles. What little bit of learning curve involved in setup will pay off in spades for years.
I'm glad a lot of people use Skype, because it means they're spending less on calling, but Skype has problems, they aren't always the
cheapest solution, and you can't use the service without a smartphone, a computer, or a USB toy that requires a computer. All are options that chew up more electricity and cost more to implement. Use a VoIP/SIP provider and an ATA, and you get cheap phone service with the convenience of landline use while still retaining the smartphone option (and even some featurephones that run Symbian S60) if you like that sort of thing.