I did quite a bit of research last August prior to buying mine. Firstly I don't believe there are any unregistered ones left at all in the UK now.
There was only one 2015 red one I found with no miles on it but I didn't get on with the sales guy so although I wanted the bike I didnt want them to have my money., That was up for £15k. That was sold a couple of months after I saw it. I have a good relationship with a well established Honda dealer near me and know them well enough to talk about stuff without any BS.
So I went hunting again and found mine, a black 2014 with only 16 miles on it and paid £15k give or take a pound. They were £18k new as far as I can make out. So I was reasonably happy with my deal. This dealer was great and it was a much nicer experience. Find another as they say......
If you are looking now prices seem to vary between £12k and £14. As you probably already know they were only made 2014 & 2015. In the UK colours were black or burgundy for 2014 and a much brighter metallic red for 2015.
No matter what registration plate a bike has it will be one of these years. Mine was registered in 2016 BTW.
I looked at this forum before pulling the trigger on mine, its not perfect this bike but its pretty **** close. The main downside is lack of aftermarket stuff, I guess there is no money to be made offering such things. The only mod I have done is to drill out the two plugs in the exhaust silencer (each side). Just lets a bit more low down gruffle out. It sounds like no other! Not loud, just very meaty.
Its beautifully balanced and handles so so well. Remarkable really. If you are lucky you might find one near you so go take a look and get a feel for it. I find mine extremely comfortable, I'm 5'11 and about 18'stone. No problems with the seat at all, some owners do change theirs though. Personal taste.
If you do have questions throw them up, you will get honest replies I am sure.