Optus recently reduced the Doro Phone Easy 615 Mobile Phone to $99, price includes delivery. Phone is locked to the Optus network.
Why am I posting this? After trying several others, found this phone the easiest to use for a relative who had problems using other phones. Great for seniors and others to use, as the name suggests, because its purpose designed so, see the manufacturer's spiel here: http://www.doro.com.au/products/Mobile-phones-and-accessorie… Highly recommended for that purpose, or anyone else who just wants a simple phone. One feature it has is that all (both incoming and outgoing) SMS text messaging can be turned off completely using the phone's menus, which is handy for those who have trouble dealing with incoming text messages. Also the included cradle is easier to use than a plug in charger.
Although the phone is network locked to Optus, ours accepted a sim from Savvytel (uses Optus' network) without a problem. If wanting one that is not network locked, they are around $150 on eBay.
From manufacturer's website:
Doro PhoneEasy® 615
Easy to use clamshell camera phone
An elegant and durable clamshell phone for answering and ending calls with a simple flip. In addition to raised edges, soft touch coating and widely spaced, concave keys, Doro PhoneEasy® 615 also has an easy to use camera that lets you take and send photos in a snap. Other features include charging cradle, enhanced sound, Bluetooth® and direct memories and SMS button.
Easy to use camera with flash
Easy to read text and display
Extra loud and clear sound
Trust me, my 92 year old grandfather can use this phone.