Kevin,

Costs at the schematic design phase would be cheap - typically less than a
week is spent working on a model at this point (depending on size &
complexity).
At DD and CD the costs increase depending on size and complexity of the
project. CD being more costly than DD.
The only standard that I know of that holds true for energy modeling is
"you get what you pay for." Even in today's economy energy models are
fairly well sought after.

What I do for a detailed CD level model is estimate hours based off a
square foot basis, our typical analysis used to take 1200 Sq. Ft. / Hr.
I've been able to develop a streamlined process using Revit - gbXML and
Trace to get the amount of time down to about 7000 Sq. Ft. / Hr. This is
for a building that is in construction, the architectural design is already
in Revit, and the building was built "correctly" in Revit.

Your case is a bit more intensive. The efficiencies that are incorporated
by gbXML and Revit probably don't apply because you probably don't have an
existing plan in Revit. I would default back to the 1200 Sq. Ft. / Hr. plus
some time for calibration. For a calibrated energy model LEED NC v2.2
references the International Performance Measurement & Verification
Protocol Volume III April 2003 (www.ipmvp.org).

I would also try contacting Jeff Haberl, he contributed to "writing the
book" on energy modeling along with many others of course. I've seen many
of his posts on this BB. He is also sited in the IPMVP on the technical
committee and new construction sub-committee. I'm sure he can give you a
good idea of pricing for your scenario.

Take care,

Shariq Ali EIT, LEED AP