>This is a much easier question, its called your consulting rate. In
    >the San Francisco bay area its between $50 and $175 per hour and I'd
    >guess that single PIC circuit would be expected to take somewhere
    >between 4 and 16 hours to develop, depending on the complexity of the
    >peripheral circuitry.

    4-16 hours??? to develop a circuit that actually does something?
    don't you mean more like 4 months?

Um, people rarely hire consultants who need to diddle around for four
months to make a circuit and software to do what they need (unless its a
project that would normally take them 6 months!)  To deserve $175/hour you
ought to have a veritable library of circuits and software templates that
you can build stuff out of "pretty damn fast".  I can imagine any number of
"quick, we need one of these" sorts of circuits based around a Stamp-1, an
rs232 level shifter, and an I2C peripheral of some kind that could be
stamped (heh) out in four hours and be worth $700 to someone.  Of course,
going that route the second one will cost close to $700 too, and pretty
soon it'll pay to spend $1400 plus expenses to get a dozen of them put on
custom circuit boards instead of kludged together in a prototype area.

Keep in mind the reasons that companies will hire a consultant in the
first place.  They want things:

FASTER: either "it'll take Chris a month to come up to speed on
        microcontrollers to the point where it will take him two days
        to do this" or "we don't have anyone who can do this, nor anyone
        who has time to learn to do this, and it will take us two months
        to find someone to hire, plus time for them to get oriented before
        they start doing real work..."
CHEAPER: "Sam could do this, but I'm not going to have a $60/hour PhD in
        physics who's doing work worth $200/hour to the company play with
        PICs when I can get Andy to do it."  Or "hiring an employee to do
        this will cost too much overhead, and we won't have anything for
        them to do afterward (but we'll still be paying the salary!)"
BETTER: "last time we tried to do this internally it took two months to
        iron out all the bugs.  This time we should just hire an expert!"

BillW