The Anchoring Advisor

Advise me on the opening move in this negotiation.

The negotiation: [DESCRIBE]
The range of possible outcomes: [DESCRIBE WHAT YOU KNOW]
Who's likely to go first: [DESCRIBE]

Provide:
1. Whether I should make the first offer or let them (and why)
2. If I open, an ambitious-but-justifiable anchor and how to support it
3. How to justify my anchor so it sticks rather than gets dismissed
4. How to respond if they anchor aggressively first (re-anchor, don't just
   counter)
5. The mistake of anchoring too softly out of fear

The first number shapes the whole negotiation — help me set or reset the
anchor well.