Not different specs as such, but loads of mod / hots-ups etc. Graphic chasis, heat-sink motor plates, one-ways etc. You may find that some will prefer a standard as box model, yet some would prefer a heavily blinged version. Condition will probably have the most impact on the price you can get.
Its amazing what people will buy to put on a shelf
.
My own view is that RC cars are there to race
