Congrats on making the step towards a purchase!
My only suggestion on how to get the best deal right now is this- don't buy new. Right now there is an amazing amount of boats on the market, many with very minimal hours. The hull warranty and engine warranties of these boats are transferable, and for a boat 1 or 2 years old many of the bugs are often worked out. As a new boat owner, most of these boats will be set up properly with electronics, etc.
If I had the money, I certainly would love to buy new and deck the boat out exactly the way I wanted...but I also know exactly what I want. If you are not sure EXACTLY what you want, buying a next to new boat is a great way to start. If it turns out that you really want something else, you can re-sell it without the marked depreciation of a spanking new boat.
That being said- if you plan to buy new, the best deals are going to be old inventory- last years models, etc. Be aware that Yamaha is coming out with brand new outboards this spring which are a technology jump. If I was buying new, I would either make sure I get a significant discount on the current style power plants that weigh a lot more than the new styles, or tell the dealer to wait until the new motors come in. Yam 250's right now are definitely getting cheaper while old inventory depletes.
Things that are very negotiable are electronic installs, engine services, etc. Things that the dealer can control without cash outlay are the best ones to ask for. You pay for the fluids, and the dealer services the engines, winterizes the boat, etc.