Engine dyno time here in Oregon varies from $500.00 up to $750.00 per day.
Their are several machine shops that have engine dyno that will only dyno engines they build and do all the machine work on
I had my bracket car on a chassis dyno in Medford, OR last month for around a half day, we made 6 pulls on it and did some timing and jetting change on the engine. The dyno owner is a drag racer also and ended up charging me only $100.00 for that time and then came out to the local drag strip for the evening also to see my car run