PIAGGIO NRG POWER 49cc help

Hello everyone, my scooter model is PIAGGIO NRG, first registered in 2011-07-30, the colour is black. The scooter itself tends to break down from time to time but I always manage to find an easy fix. It has a new cylinder and piston that I've just finished breaking-in, around 200-300 km on that. The total mileage is over 20k kilometers on the dash but only 10k on my technical check paper, don't know what's up with that, the scooter manages to achieve a top speed of over 90km/h, although the speedometer broke down just a little while ago and needs a new wire. The exhaust leaks air but again, should be an easy fix, there are a couple of scratches on the front left side plastic and a small rupture in the driver's side front plastic. There is an occasional rusty bolt and nut here and there but nothing too major, it has a new accumulator aswell. I would like to know how much I would be able to sell this scooter for reasonably.