I read an article recently that pretty much sums up what you're saying:
As you already know, the answer is to this problem is, stop being a developer and become a consultant. I'm sure that's why you're reading Weiss' book. I'd say the first step in that process is don't be so quick to present a proposal. This isn't something you can do if you're playing the RFP game, but personally, I avoid competitive bidding situations entirely. Most of my prospects aren't even talking to another developer. That's because I seek out and associate with relationship-driven individuals.
The problem with proposals is that they can become a crutch. We spend too little time engaging our prospect in meaningful dialog then throw a proposal his way, hoping that it will do the "selling." Personally, I do not submit a proposal without the firm commitment from the client that they will hire me. Obviously, this requires much more upfront conversation than the typical "prepare a proposal and hope" method. And guess what? It also builds the relationship. By the time I've had a few conversations of this manner, the prospect either sees me an an expert he can trust, or I've discovered he's price-driven buyer and we've gone our separate ways.
The other part of the problem is in your comment, "if I get a call for a new site I may not know the owner..." By the time someone "gives you a call" they are already in "buying" mode. There's nothing wrong with having people call you (in fact, it's a great thing), but consider finding ways to engage prospects before they are in buying mode. How much more time does that give you to build breakthrough relationships?
Does that help answer your question?