So the purchasers of the software you write should obviously be writing
their own as they're paying for the business license of of your employer
as well as the secretary and your benefit and fringe package and the
machine and tools you're using to develop with.

Right! NOW I get it...

That's not the same. They are paying for a product and they are have to
pay for R&D. That goes for anything you buy off the shelf whether it is
software, a toilet valve, or an A/C. I am not complaining about the
price of building supplies, now.

I have done contract work where I had to go to the customer's site to
write software. But even then, we negotiated on a rate (time and
materials) and that's all I charged for. Granted my rate was very high
but they knew that going into the deal. So, I expect the same when some
workers come to my house to do work. I don't see the justice in paying
mexican's $150/hr to paint my house, which is about what it works out to
when you do the math.