>        My question is what is the proper amount of MONEY for a device such as
> this?  Or any device?  Being new not to engineering but to the business
> side of things I'm really in need some comments or thoughts. Do you charge
> by hour or project?  Or importance?  Any "rough figures" would be
> appreciated.

The proper amount of money is "cost of parts + cost of assembly + cost of
overhead + amortized development cost+profit". There are two numbers you really
need to know before you can accurately price your product, how many
per year you expect to sell, and how many total you expect to sell.

So let's PIC a few numbers :-)
        Cost of parts + assembly        say $5.00 (USD)

Annual budget for FrobotzEngineering
        rent+phone+salary+medical+dental+vacation       say $120,000

Total Expected market for the FRB-1     say 24,000 units @2,000 per month.

Cost to develop the FRB-1 in say one year or $120,000.

Now amortized cost will be $120,000 / 24,000 units or $5.

Now the cost of overhead (for one year of sales) is $120,000 / 24,000 units/year
 or $5.

"Profit" (spent on advertising, new product development, and
physical plant (ie new or better test equipment) $5.

Look's like you'll have to sell it for $5 + $5 +$5 + $5 = $20.

That's if you can sell 24,000 units. If you can only sell 2,400 units
this becomes
        $5 + $50 + $50 + $5 = $110

If you want to advertise, add that in to your overhead (it helps unit sales
but increases costs)

But this is only if you want to run a business, you can give away
your development costs and living costs (or have someone else
pay them, like some 9 to 5 job for some company) which will
lower the price, but don't kid yourself that you are being 'fair',
your just giving away your time.

--Chuck