Bikes generally hold their value a lot better than cars. Also, the prices are consistent, a similar bike with similar milage will be pretty much the same price everywhere. Any decently looked after medium sized bike will probably never drop below £1500. I think it’s because to keep a bike in good mechanical order takes more time, effort and money than a car, so people can see the value in something with a service history, good tyres and a new chain and sprockets.
What people (dealers especially) are scared of is milage. Why I don’t know, but as soon as a bike has a perceived ‘high milage’ dealers won’t want it and private buyers get scared.
Take my Honda NC700x for instance. I paid £4300 for it at 8 months old. That’s nearly £2k off a virtually new bike…… because it had done 8000 miles in those 8 months (That’s a lot). BUT it came to me with a new chain and sprockets, new tyres, new brake pads and a fresh service , and with 16 months warranty. Bargain!
Now, at 4.5 years old it has 47,000 miles on it. Which in motorbike terms is stratospheric to lots of people. But it’s been serviced on the dot, treated fairly gently (apart from the winter miles) and wants for nothing. The NC700/750 forums never bring up any horror stories with these bikes and as we all know the engine is half a car engine, low revving and low stressed, it’s fair to say you can’t kill the dmaned things if you try. There’s several with way over 100k on the clock with no issues at all. Apart from normal wear (Tyres, chains, pads) I’ve only put 2 sets of rear wheel bearings in it (One under warranty, the second myself for about £7.60 for the pair) and it just works perfectly, metronomically reliable.
So, if you want something cheaper, search for a well looked after high milage bike!