Costing table for the robot hardware.

        item                                                                          cost

picaxe microcontroller                                            $50.00
twin gearbox                                                          $22
sensors, emitters                                                   $18
wiring +circuit boards                                             $25
batterys                                                                 $8
wheels                                                                   $2
castor                                                                    $2
resitors, capicitors                                                  $10
assorted extras                                                       $30

total                                                                        $167