If you feel you understand all of the intricacies of a real estate transaction and you understand market prices why do you need a real estate professional at all. You should just go get a contract from your local stationary store and write it up. After all it is really easy and any issues that come up you should be more than capable to handle them. After all, you sound like you have a lot of experience in real estate purchases (I enjoyed your highly complicated and intricate question about property taxes) Sarcasm intended! I'm not trying to piss you off but... You may not know what you don't know.
Vincent, most serious buyers do a lot of research into the market, similar to what you have done. Ideally the process, negotiations and closing goes smoothly. That is a sign of a good agent (on both sides of the transaction) more often than not it doesn't. Appraisal issues, property condition issues and financing issues lead the list of potential problems that can derail "closing the deal." In the hills, you may have additional concerns with foundation, sewer/septic, site, slope and drainage issues etc. Hiring an agent or and attorney does not come cheaply but given the size, complication and liability of the transaction, it shouldn't be.
Our industry is experienced based, the longer an agent has worked as well as the variety of transactions we are involved with provides us with the experienced necessary to handle most transactions. Your transaction may appear to be routine or easy (and hopefully it will be), but that is like saying taking one's appendix out is routine. More often than not removing the appendix is routine but every once in awhile the appendix bursts, then what?
I suggest that you work with agents based on their knowledge, experience and services and not their initial pricing. Don't disregard their fees or "pricing", but don't use it as the initial level of scrutiny/screening. FYI, you are asking agent's to take on a lot of liability for little in return. Most experienced agents would consider this a bad business decision.
Coldwell Banker - Downtown Los Altos