I bought a personal plate on my car a few months back (cost me £180 inclusive).
The plate wass still advertised on national Numbers website for £1600.00 for awhile after i bought it (privately i might add).
When i emailed them for an explanation i never got a reply but it is no longer on there.
I just think they try there luck advertising unregistered numbers at daft prices & don`t update the site very often.
Having said that if anyone is daft enough to want my plate for £1600 i won`t argue 