cost of IAQ testing?

We propose IAQ testing on a per test basis. Often times we are asked to determine the required number of test areas for the project teams and the lab fees directly correlate with the number of test areas. I'm not sure how pricing by SF would be possible.

The fees are run between $700-$1100 per test area for 3 or more test areas. They decrease at certain breakpoints. This price always includes RUSH lab turnaround, 24 hrs from lab receipt.
There can be 100% price premium from the labs for RUSH results but standard lab turnaround can be 7 business days. If the team had 7 business days plus testing dates in the schedule they would probably choose the flush option and not risk failing the IAQ test.

Our proposal process is almost identical to the aforementioned. The major difference being we bid for standard lab TAT (turn around time) and breakdown the fee increases for the expedited TAT in our proposal.
Per sampling location our fees typically run between $500-$1000 depending on the sampling frequency. In addition, site visits, report time and travel time are factored into the final fee; all factors which are project specific.
I like Thomas's approach as far as bidding all projects for expedited TAT. I'd estimate 90% of the projects I've been involved in are completed at the very last minute with no time in the construction schedule for re-testing. I call it the "Hail Mary" IAQ test!