Number Plate B14 GTR

Selling my number plate I have it on retention B14 GTR, I had an adapted 4 so it looked like a G so B1G GTR. Its valued at £2000 by plate trader.

I'm not sure I will ever understand what makes plates collectible and worth money in the UK.

Is it that big of a deal over there?

It's hard to explain I suppose so first you need to know the history of UK plates.
Number Plate History
Index marks of one or two letters were issued to the various licensing authorities in 1903 and most then started to issue registration numbers starting at 1. It is believed that the first registration mark issued was DY1 - in Hastings, Kent on 23 November 1903. (The registration mark A1 was issued in London some time later)
A three letter/three number series was introduced in 1932
By the mid-1950s all marks had been allocated, so marks issued by some authorities were reversed with letters following numbers. Others continued to issue 'forward' marks (numbers following letters) until the mid-1960s
The addition of a year suffix began in all authorities between 1963 and 1965
The registration year ran from 1 January to 31 December until 1967 when it was moved to 1 August
The registering and licensing of new cars was centralised in 1974 with the establishment of the DVLC, now DVLA in Swansea
The year 'prefix' system with a leading single letter to show the year of first registration began on 1 August 1983 with the introduction of the 'A' prefix. (This series ended with 'Y', which ran from 1 March 2001 until 31 August 2001
Q plates were introduced in 1983 and are issued to kit cars and some imports where the date of first registration can't be established
The current system with the two number 'age identifier' in the middle of the plate was introduced in September 2001

So basically people want the plates with no age identifier on pre 1963. These tend to be the more expensive especially if they have someone's initials or spell a specific word. (rude words are not allowed we are British of course!) after that plates which spell something which can have age identifiers but people use the numbers as letters 4 becomes an A, 5 becomes an S and so on. Marks is an age prefix plate on a B which makes it an 1985 registered plate. When it was initially registered it would have been nothing special. The value is when nissan produced the GTR and to have that on a GTR some people are willing to pay big bucks. For me I don't get it either but you did ask.!

That's quite an explanation! thank you!. In America, plates don't stay with the car for life, only with the owner, every time you buy a car, you get your own set of plates, and you can personalize them with anything you want (within reason, can't be vulgar). If I wanted a plate that said GTR something or other, I could easily do so, provided someone else didn't already have it.
My current plate says "OMGTIR" hahaha

Yeah it's big business here with some of the early plates going for tens of thousands of pounds. I would rather spend my money on a holiday personally, but each to there own. Good luck with the sale though Mark!