As far as Marin is concerned, I have seen houses with pools go faster than others recently. This is not the case before.
Having a pool is really a personal choice. An appraiser told me once that a basic, functioning pool probably adds $20,000 to the appraised value of the house. I think half of the people who want it and half totally against it; some young families worry about their kidsâ€™ safety, and others want it for the kids and parties â€“ My husband refuses to buy one due to additional maintenance required.
I have a custom, luxury home in Novato (northmost and least expensive town in Marin) on market now. Quite a few buyers walk into the house said that they love everything the house has to offer but they want to have a pool; and more houses in that price range with pool went into escrow than others just this year.
I have never heard about discussion of water cost as a reason for not wanting a pool, but mostly maintenance issues. Also, for houses in the low to medium price range, it could be possible that added maintenance cost of pool which could be a stretch for home buyers who are already tight on budget.
Of course, solar energy is also big now, so for a heated pool (in Marin, other than Novato, which is the warmest and sunniest town in Marin), you might want to look into that.
Sounds like you might be looking at Marin and the East Bay. Great choice - I am passionate about Marin. Let me know what you are looking for, maybe I can help you narrow down your search.