What was specially interesting for me is how they achieved the low cost -- especially their use of vibration motors!:
"There are four main designs features that help keep the AERobot low-cost.
1) The robot electronics are designed to use only SMD components which can all be placed using a pick-and-place machine, drastically reducing assembly costs. Additionally, all components are mounted on a single side of the PCB, cutting assembly cost in half when compared to a PCB with components on both sides. All remaining assembly steps are very simple and can be done by the student in a few minutes. The PCB also doubles as the main robot chassis, further reducing robot cost and complexity.
2) The use of vibration motors greatly reduces the overall robot cost as vibration motors are cheaper than standard motors, and don’t use the extra hardware found in most robots such as gearboxes and wheels.
3) Using a USB interface built directly into the PCB removes the additional costs, incurred by most robots, of an external programmer and charger, which can easily double the cost of a complete robot system for robots at this price range.
4) AERobot uses purely optical sensors (the infrared transmitters and photodiodes) which have no moving parts, are generally lower cost than most other sensors, and are robust to dusty environments."
Cool, and it looks like another alternative is Pi-Bot in case someone wants something that can be ordered now (more expensive though): http://pi-bot.org/
Both bots work with Arduino and the Minibloq visual programming environment: http://blog.minibloq.org/
"There are four main designs features that help keep the AERobot low-cost.
1) The robot electronics are designed to use only SMD components which can all be placed using a pick-and-place machine, drastically reducing assembly costs. Additionally, all components are mounted on a single side of the PCB, cutting assembly cost in half when compared to a PCB with components on both sides. All remaining assembly steps are very simple and can be done by the student in a few minutes. The PCB also doubles as the main robot chassis, further reducing robot cost and complexity.
2) The use of vibration motors greatly reduces the overall robot cost as vibration motors are cheaper than standard motors, and don’t use the extra hardware found in most robots such as gearboxes and wheels.
3) Using a USB interface built directly into the PCB removes the additional costs, incurred by most robots, of an external programmer and charger, which can easily double the cost of a complete robot system for robots at this price range.
4) AERobot uses purely optical sensors (the infrared transmitters and photodiodes) which have no moving parts, are generally lower cost than most other sensors, and are robust to dusty environments."