I was recently on the interview panel for a new appointee - we chose someone, but then the chair was heading off on annual leave so deputised the paperwork to me... Candidate accepted but wrote a quick (one short paragraph) email laying out a case for starting at a higher point on the payscale, HR emailed me to ask what I thought, I said I thought they had a good case and we really wanted them, and HR said...
Yeah, OK.
And now I'm a bit flabbergasted. And embarrassed. Looking back, I started WAY below where I should have been on the pay scale, and I'm still clawing it back. Gah. So the take-home message is, negotiate! Politely and with a good case, obviously, but go for it!