New purchase negotiation rules of thumb

[Sawbonz]

Greetings,

To begin, yes I did search the forums. No, I did not find what I need. Maybe it is the search bar, maybe it's me, but here goes...

I hope that we will soon sell a large item that will put us into the market for a new semi-custom catamaran to be built and anticipate being in the 3/4-1 million dollar range. In the past I have purchased many larger items and have some idea of what to offer and how to begin, but not on these.

Specifically, I would love to hear your experiences, especially if recent, on how you:
1. Determined your initial offer (and whether it was accepted, how much back and forth was involved). Was anything other than the asking price even considered?
2. How you would (or did) account for changes and upgrades in the build process, i.e. Pay cost plus for add-ons, difference between an allowance and cost of acquisition for upgrades, etc.
3. Handled payment schedules during the build
4. Handled exchange rate fluctuations
5. Any terms that would be important to put on paper
6. Did you use a broker?

Also of interest would be the experience itself!

While I appreciate that our budget may be more than many I would prefer not to dwell on it. Thanks for not making it an issue.