Anybody who is in the know could you possibly advise how much private plates are worth very roughly.

I have 2 plates that are 2 numbers and 2 letters.

63 **
78 **

Any idea on value?

Would say between £2,500 - £3,500 depending on the initials, some are rarer than others so fetch more. I bought one from reg transfers which was advertised at £2,500, put an offer in of £1,200 and got it.
If they are JF initials I may be interested at the right price.

£4k to £40K - seriously depends on what the letters are.

JF would be worth a lot, JZ not much!!!!!!!!! probably best to go onto a web based private reg company and look for similar no's to give an idea. Some companies do an e-mail valuation service. But beware some also mark up their offer price by 40% to 50% for a straight purchase.

At the moment the market is slow, very slow due to the credit crunch...

Needless to say my REAL surname is not FRESH, as much as I wish it was. I would also like to change my name to Max Power as did the great man himself...Homer Simpson