Sigma BC 506 Cycling Computer @ Cell Bikes $19
I'll give Cell bikes credit. Every couple of weeks they put something out at a good price. The only thing I dont like here is that their shipping, at $8.95 is a bit of a killer (tested postcodes 2000 and 6000).
But anyway - if your anywhere near 148 Parramatta Road Stanmore NSW 2048 you could pick it up.
The average price for the same basic unit is about $28-$30. Doesnt come with a cadence so probably more something youd pick up if you already had one.