How long is a piece of string?
I guess your initial query has to deal with what is a 'good' wedding photographer. These days anyone and everyone has set themselves up as a wedding photographer, therefore the standards will vary greatly.
I remember when I started out nearly 16 years ago when you searched for a Bridgend wedding photographer there were around 6 of us now theres 90 and still growing!
Quality of the photography should really be a given if someone is calling themselves a wedding photographer unfortunately this is not the case. Also the professional conduct and behaviour before during and after the wedding is vitally important. Well it is to me. I am always in a 3 piece suit and a matching tie to your colour scheme, after all I am attending your wedding.
So study the wedding photographers web site not just their pretty one off images. Ask to see complete wedding galleries. Make sure their style matches what you are after in your wedding photographer.
Pricing according to the National Survey seem to say £24K for a wedding. A standard rule of thumb has been photography should be about 10% of your total which would be £2400!
Bridebook state: £1400-£1600 is the UK average for a wedding photographer.
So you see just within two searches you are getting varying price points.
My approach has always been 'how much would I pay for me if I was booking me'! Not very scientific but more of a moral approach.
I compare my work to the ones who charge £3000 plus. I've probably photographed more weddings than they have and have exactly the same equipment if not better. I can justify my prices based on my overheads, my years of experience, my service and my professionalism on the day.
See my prices here: wedding packages