PricePoint is key in any service.
We started a similar service for The London Silicon Roundabout called TechStartupJobs and started at about £5 (about $8) to test market within our community of 1000+ tech individuals and companies.
Once you prove value price can be adjusted.
Didnt mean to preach but this is 101 Pricing Services that we mentor to our Startups (http://www.techstarthub.com/startup-mentoring/)
Best of luck anyway!
Rgds Shawn Techmeetups