[Stonehenge]

This is true. If it's a ritzy neighborhood, you may be able to presume a little.

And in my engaging the customer in conversation, I try to get as descriptive an idea from them as I possibly can of the project scope.

From there I can sometimes give them a ballpark estimate right on the phone, which I used to hate to do, but now I find valuable in qualifying leads. If I say "...something like that will probably cost in the neighborhood of $10,000. Does that sound like about what you'd expect for a price?", I listen to the response, and my next words are contingent on that answer.

Once I recognize a bad lead though, I'm usually pretty good about ending things quickly and on good terms. It's just breaching the budget question that's hard......