Bob:

The prevailing wage for salaried P/A employees with 2+ years is $63K in
Virginia. This figures does not include the value of benefits which is
usually equivalent to 15-40% of the salary.

I don't moonlight anymore, but I used to charge 1.5 the hourly rate I was
getting from my employer.

A few rules of thumb I used:
* I increased the hourly rate by 10-20% if it is was very short contract
(<100 hours).
* I increased the hourly rate by 40-200% if deadlines were tight or the project
was very important to the Client. I assumed I may have to miss a or two at
my regular job if the dealines were tight or if the client wanted to meet
to discuss the project.
* I didn't accept fixed priced projects unless the analysis was already done
and the specs approved. My assumption was that if I had to do the specs,
I would have to interview several users and thus miss a day or two of
regular work.
* I never told any co-worker that I was moonlighting...

Hope it helps,

Daniel