One of the golden rules of negotiation is..the first party to give a solid number is the loser.
That's common folk wisdom but every piece of evidence I've found on this suggests that the opposite effect is dominant due to anchoring (http://en.wikipedia.org/wiki/Anchoring).
Various studies have shown that anchoring is very difficult to avoid. For example, in one study students were given anchors that were obviously wrong. They were asked whether Mahatma Gandhi died before or after age 9, or before or after age 140. Clearly neither of these anchors can be correct, but the two groups still guessed significantly differently (average age of 50 vs. average age of 67).
Thus, despite being expressly aware of the anchoring effect, participants were still unable to avoid it. A later study found that even when offered monetary incentives, people are unable to effectively adjust from an anchor.
You need to do the background research, figure out what an actually reasonable range is, then make the first offer ever-so-slightly unreasonable on the upside. Just making that offer will shift their perception of what reasonable is.
As others have noted, this is easier when you have a great alternative.