The one thing I did that got us to the right number was to first do all kinds of research on this forum. I poured through all the build pages, all the new posts, and learned as much as I could about everything, which helped me focus in on what exactly I wanted in my new pool, and what was important when it came time to talking to the builders.
For example, there are a ton of gunnite pool build posted and updated everyday. Now I'm not getting a gunnite pool, but thats not the important part. All the equipment, process, problems, solutions that go into these builds is kind of the same for any pool. While I found all the build fascinating (still do everyday), I found I learned a little more every day. It was kind of like learning a new language.
Rather than relying on having a PB tell me what was going to be included in the price, I told them what I wanted. Different builders use different equipment, so its not apples to apples. But I knew I wanted automation, a large cartridge filer, a SWCG 2x my pool volume, etc. By doing this, we were able to talk with pool builders with some confidence, and build the package that worked for us. A lot of builders in this area for FB have "packages", which is a good starting point. They will have filters that are probably too small, no SWCG, and maybe not enough lights. But I liked starting with their package, and they knew my requirements up front as well.
When it comes negotiating a great deal, in my experience with the process in the SW suburbs of Chicago, there doesn't seem to be a lot of room to haggle on prices. Like all parts of the country, PBs are busy with this spike in demand. But unlike other parts of the country, the building season is shorter. All the builders we spoke with were within a couple of percent of each other.
PBs in this area are booking builds for late spring/summer 2021 already. They get so many inquiries for new builds, a lot of them don't even bother to return phone calls or emails. They are that booked with work, they will actually just ignore potential new customers. I was able to work with my PB on the pricing of some of the options I wanted, but in the end, most of the PBs are going to sell their pool/product/service to someone who is willing to put down the deposit first. There is little interest from them to concede prices for one customer, when they have a few more lined up behind them waiting to pay the price the PB is asking.