The cost to replace a torque converter depends on the make and model of vehicle and how hard it is to get to the transmission to change out the torque converter.
To change a torque converter the transmission has to be disconnected and unbolted from the engine which requires removing the transmission at least partially to install the new torque converter.
A new replacement torque converter costs between $150.00 to $500.00 depending on the make and model of vehicle so if you do the job yourself it will just cost your time and the cost of the new torque converter.
But if you have a shop replace the torque converter which is recommended for someone without the knowledge or tools to remove the transmission then the cost of a shop replacing the torque converter ranges between $400.00 to $1,000.00 for the labor and then the cost of the torque converter.
The labor I charge is around $400.00 to $500.00 depending on the make and model of the vehicle and how involved it is to get to the transmission and torque converter.
Then the cost of the torque converter.