I've only purchased one Like 200i, so I can't speak from a lot of experience. However, I paid about $3300 for mine (zero miles) and the dealer threw in a windscreen and a 3/4 helmet of dubious quality, but good enough to get me home. First service at about 500 miles was also free. $2500 seems like a good deal for only 54 miles. Since is was a demo, look closely for signs of having been laid down. Probably cosmetic and no big deal, but one never knows...Give aways would be be scratches on the chrome handlebar weights or the outside edges of the mirrors.
Good luck with your purchase. She's a sweet scoot!
Peace and Ride Safe.