I do wedding photography on the side of my full time job. I started in August last year and started out charging around £500 for a whole day (around 10-12 hours). Now I charge between £650 and £850 (depending on the package and the client's requirements) which seems to be the going rate for what I offer. I could probably charge more, but I don't want or need to right now.
If you're going with a full time wedding photographer you'll probably be looking at around £1000+. However you can easily pay anywhere between £500 and £5,000. It's a massive spectrum and really it depends on what you want and who you want.