*An alternative economic version of High torque motor available:
Johnson High Torque DC Geared Motor 200RPM
200RPM 12V DC geared motors for robotics applications. It gives a massive torque of 13.5Kgcm. The motor comes with metal gearbox and off-centered shaft.
BUY A MOTOR WITH ENCODER
I just bought two of this 200 rpm 32 kgcm torque motors and i used it in my robot of 15 kg weight.It works properly without any problem.its very efficient motor.u can buy it without any hesitation as the torque is quite sufficient for 15 kg bots