As always, condition is going to be everything to establish a price.
Until we see the pics and description of condition you'd show on ebay, we have no better idea than just a wild guess. ?
Obviously, a new Bonniksen still in its box is a completely different prospect to a battered old relic that been through the wars.
And a pristine new KH250 is different to a worn old bike missing bits and been in 6 accidents.
A freshly restored speed twin engine versus a worn old old lump sitting in a damp shed for 50 years.
If you get our drift....
Putting them on ebay and see where they get to, if you are serious about selling, is the final arbiter of prices ??
Dusting them off and a bit of polish always makes an impression on buyers....