Cheapest ever road bike with STI? half-price $248 + $15 deliver from BigW online.
The Shimano entry-level ST-2300 16-speed.
edit: not available. Probably sold out, but the website has been flakey recently.
http://www.diamondback.com.au/bikes/road/sr1/
S 155-170cm / M 170-180cm / L 180cm+.
Lightweight 6061 Alloy Road Frame
Cromoly blade fork for comfort & control
A head parts and racing handle bar
Alloy Double Wall 700C rims
Alloy 3 piece crank
Kenda 700 x 23C road tyres
Shimano 2300 equipped with STI shifters
Quick Release Alloy Hubs
Lightweight Alloy Brakes
Quick Adjust seat post
Arrives 99% assembled
wow, cheap cheap cheap!
but… usual caveats apply to department store bikes… assembly, maintanence problems… etc etc