Tracking total cost of recruitment

Summary

Is it possible to assign annual cost to specific referral sources?

Content

We are looking to start to truly track the costs of new hires in relation not only to the expenses candidates incur, but also assigning proportional cost to each one based on the annual cost of their specific referral source. For example, say we hire 4 people that were sourced to Monster, and lets say Monster cost $1000 a year. Each person would effectively be costing the company $250 in addition to any additional expenses they incur such as lodging or relocation. Then we could compare that to CareerBuilder, who we may have hired 5 people from but it costs $2000