Thanks. You can definitely save tons of money by doing an owner build. If I ever were to build another pool, I would definitely do it by owner again. However, an owner build is not for everyone and it has its cons as well.
PROS OF OWNER BUILD: You can pay contractor level pricing for most items. From excavation and plastering to water features and tiles, you can amount to lots of $$$ in savings. You also get to learn a lot about all the ins of how your pool works, making you be able to troubleshoot future problems with more ease. Also picking finishes and adding upgrades along way really don't cost you any extravagant builder "add-ons". For example, the day of plaster I decided to switch from standard plaster (diamond brite super blue) to a blue based diamond brite tahoe blue, and only had to pay the difference in "per bag" cost, which was only about $200 total. I was also able to schedule contractors visits to fit my convenience. Since I paid for pool by saving cash as I went, this allowed me to budget with more ease and less stress. I know builder payment plans required large payments scarred in 3 or 4 installments only, to be paid when certain build milestones are done.
CONS OF OWNER BUILD: Time is single biggest negative. Time for researching and learning about the process (thanks TFP!). Time for finding, requesting estimates and choosing contractors. Time monitoring contractors and at times babysitting the project to assure it is done to your liking. Time for going and pulling permits yourself, etc. Also, sometimes when things are not perfect (and believe me I had my share), I wished there was somebody I could call to b*tch and compain at. Also, at times I had to get my hand dirty "physically speaking", and do come clean - up, shoveling work myself.
Builders serve a much needed purpose. Albeit the bad apples in the industry, builders remove the stress out of the construction process and handle all of those headaches. So, if either money is not an issue or you are not comfortable with the builder cons I listed above, I say go with a builder. Just remember, a $40K by owner build is probably a $75K+ builder build. I spent $17K for a build I was quote upwards of $27K without any of the add-ons I ended up placing and no automation system.