Not so high really, if people really want that stock controller, or whatever replaced.
But the broken motor is worth it's scrap metal price more or less. Nobody pay much for broken.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE
Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum
See battery technology section, FAQ thread at the top of the page for lipo noob info.