Ya, a little confusing.
O2 sensors have a heating element with a target temperature of 600 degrees, so if they aren't getting hot, the element circuit is bad, the wiring harness is broke (bad connection), or the ECU is no bueno.
TPS (Throttle Position Sensor) simply tells the ECU the position of the intake butterfly and adjusts fuel injection accordingly. If the value does not match the actual position, the fuel mixture goes out the window and the engine won't spin up correctly.
None of these issues are a big deal for a good technician, and comes no where near $1700 to address. And all of it is easily diagnosed with the proper computer equipment.