I know a very good logo designer -- but she's not a UKBF member. You might like to wait and see if a member can do it; if not, PM me and I'll give you her details.
As for price, you can pay anything from £100 to £1000 depending on what you want. You will find designers who charge less because they are often working on borrowed (a euphemism for 'stolen') software and they'll give you a logo which depends heavily on tone and whizzy graphics, which you can't resize easily, which needs to printed in full colour, which dates quickly...
An experienced designer will charge you more because they are not only charging you for their technical design work, but also their thinking and planning time. They will ask you a lot of questions about your company, your values, your target market, your budget, what stationery items you need. Plus, most importantly, they'll ask how you plan to use your logo ... so that they can make sure that it is readable in all sizes and in all uses: black and white, on a fax, on a website, on a business card, on the side of a car, on television... you get my meaning.
Your logo has to be adaptable, it has to grow with you. That's not a simple request! But the logo you end up with will often be quite simple and elegant; and often witty. Perfect for every occasion and for your target market. That's no mean feat -- which is why excellent logo designers are rare.
Whoever you choose, make sure they give you a logo which is in eps format (for uncomplicated resizing); and which can be colour matched in both CMYK and Pantone (so that you can print in one or two colour, should you choose to do so).
If I can help any more, let me know.
Julie