Thats a joke but i guess they wanted to make some money... Its only worth what someone is willing to pay for it. I Saw K11TTY going in the same auction for about 45k "mental"
I have a private plate, i love them but i always find it interesting what lengths some people will go to for certain plates, especially the ones you have to read upside down, with one eye whilst drinking rum to work out what the owner thinks it says lol
I got mine years ago for £250 from DVLA, says STE and only has 6 characters so i can get on a small form factor plate "legally" will be with me till death

or change identity... lol