Can't stress enough how many leads it brings in, I had just an image with my contact details posted up for 2 years along with a number one google local rank for a few search terms and that brought in a fair amount of business.
2 months ago my full website went live and that is getting us 2 to 3 leads a week already and google has only just started to index it, oh and it has also lead to a possible magazine feature along with another TF member, watch this space!
I did mine myself but have spent more than likely a 2/3 hundred light night hours teaching myself and writing it. Even if it cost you £2,000+ I think it's worth it! but I think £3-500 would get you a half decent looking site