These come up constantly, I emailed about one and was sent full photo's, description, history.
It was a buy it now price, was told to pay then I could collect the bike!
Bike conveniently at the other end of the country, not view able.
The bikes you have noted will come up again with different email contacts.
Generally they are a buy it now, about £3000 with a different ebay name.
If you trace the sellers other items they usually have plant equipment/ jet ski's for sale.
Quite often they will have no feedback.
They usually seem to have a friend looking after the machine and are not in the country.
I have reported many in the past.
A genuine seller will not be evasive, will allow viewing, will/ usually have feedback, will not be so cheap as to get you questioning it, most people know the value of their machines.
Will not expect payment without viewing.
Hope this helps, be careful, don't get caught out.
There are several machines doing the rounds, keep cropping up with different sellers, areas of the country and contact no's and emails,