12S2P = 24 Cells. What is expensive? 24 x €6,- = €144,- + €80,- (Charger) + €20,- Wire an Cables + €150,- VESC + .. + ..
Overheating: Is not easy to answer: Air temperatures 35° in the Summer, climbing up the hills. Yes the motor will overheating. The best way is to monitor the motor temperature and shut down the ESC over 80-90° motor temperature.