Next cheapest found is $89.
As per website:
Transfer the Internet around your house using the existing network of power lines
High speed data rates of up to 200Mbps
Ideal for connecting PCs, TVs, gaming consoles, blu-ray players, TiVo and other networkable devices
AC pass-through built in - plug other electrical devices into the same power point
AC pass-through socket uses noise filtering to ensure your data signal is not disrupted by other electrical devices
Plug and play - no setup required
Extremely compact in size - fits nicely behind furniture or amongst a home entertainment environment
Twin Pack
Safety Approval SSA101230EA
This link is quite help in giving some information relating to this technology. Maybe slightly outdated, but good price nonetheless.
Edit: It looks like some members have been using Officeworks for a successful pricematch. The total price should be $65.55 is pricematched.
Has anyone tried this if it works nicely (unlike many repeaters)? Thanks