In 2006 my wife brought me a second hand Shoprider Cadiz 8 mph mobility scooter for £500, it had only been used a couple of times by an old guy, it had some of the protective film in areas.
It has been all around the tracks in the New Forest pulling a trailer with my little dogs in, I am on my 3 set of batteries, it reliable and comfortable.
Is it possible for your auntie to buy it from motablity or like us purchase a nearly new scooter and keep the money in her purse.
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.