Bluetooth Coin Scanner Solution

Requirement: I would like assistance from someone who has the skills to create a coin scanning solution which can detect all Australian coins and feed the data back to an android application via blue-tooth signalling (application will be developed to suit the output from the coin scanner) Design, build instruction and physical prototype will be required as the output of this task (I will consider just the design and build instruction in the event that location prohibits the supply of a physical prototype) Design Considerations: - Must use minimal power (battery operated) - Component costs (scanner + Bluetooth sender) should be kept as low as possible ($10 AUD or less?) - Component size should be kept to a minimum (similar to that of a digital piggy bank) - Should avoid highly complex build methods where possible (no excessive soldering, etc) - Not concerned by appearance of the hardware solution at this point - ugly is ok! Price provided should include time and materials for the spec listed above.