Moz has 140 employees and is at a revenue run-rate of ~$33mm, putting us around $235K/employee. I know companies with higher revenue/employee than us (many of those are smaller) and some with lower revenue/employee (many of those have lots of funding and are going negative to grow faster). So long as you're applying additional metrics into the equation (funding, growth rate, cost/person by location/type, etc) I think this is a reasonable baseline.

That said, there's lots of very important metrics to understand if you're trying to do a comparison - rate of growth, margins, churn, etc. - all of these figure prominently into the health of a SaaS business.