This is my second O/B build. The last one was like 10-15 years ago and learned a couple things since then. Amazingly, I am using a couple of the same subs. In Vegas, the subs will let you use their accounts at the local supplier, and the supplier works with you and creates a sub account so you get the wholesale prices (so they say, I'm guessing its bumped up a bit, but still lower than most anywhere and with the 3 year warranty, which is most important).
I have found its a lot easier than most people think, and the subs here are used to dealing with O/B and will usually give you names of other subs they like to work with, so you get a lot of opportunity for getting multiple bids. If you can afford to pay cash to some of the subs, you can save another 5-25 percent, depending on sub.
Also, the subs tell you what they do, who to call next and when to get inspections. For instance, I called up the electric sub and asked when they want to come out for pulling the wire, etc, and they said at least 2 days after gunite and we set the date.
The inspectors are easy to work with too. It's better if you happen to be home when they come, so if you fail something, they can tell you what needs to be fixed, changed or even a work around to get it passed for that part. In Vegas, its a pre-gunite inspection, and then a final. So only two inspections, and the final is done prior to plaster.
Last, because I am the PB and Owner, I can make changes on the fly without anyone telling me no. For instance, I added a bench and step out, and my steel guy didn't charge me any more, and the gunite didn't charge me anymore either. During the rough electrical I added an outlet near the pool and a light over my equipment, and only minor charges. My tile guy I just pay for the installation, and separately for the product. In any event, you get the idea. It's not as much as you would think, in my opinion, and I can get exactly what I want, and any mistakes are blamed on myself.
I just keep a folder, for bids, pictures of what I like, samples, etc. It seems to be working out fine, and the only timing issues are really my own.