I haven't been able to find any numbers related to cost via google or price sheets. How much do these services realistically cost (akamai, limelight, any of them)? Are there any good CDN review/comparison sites?
Edit: Just got off the phone with akamai sales - they determine price per client. The cost-per-gb is based off your average expected monthly bandwidth. Hopefully I'll be able to post more details as I get them.