The TD125 is a suspended subchassis belt drive tt with a low torque/low RPM a/c motor. The motor does not run directly off the mains, but a regenerative type supply. The electronics inside the tt are for this. They consist of a sine wave generator and a signal amplifier. Most of the TD125 units are not working because of problems with these electronics. An expert DIYer with experience in repairing vintage ss amps can repair this but a commercial guy may not be able to/not interested. I haves also come across a case where the faulty electronic board was bypassed and the motor was wired directly to the mains through a register, as is the case with the TD150/160. But this shall degrade the performance.
If the electronics are not working perfectly, I would not pay more than Rs. 5000 for a TD125. Also, Make sure to take off the platter and store it separately during transportation. If left in place, it can come off, resulting in damage to the motor and tonearm.
HTH