Pricing is negotiated on a client-by-client basis. Setup fees for most implementations will run between $5k-$10k. Ongoing monthly or quarterly fees will generally be based on one of these models:
Monthly user-based fees start at $3.20/active user/month
Transactional fees which are a percentage of a content sale
Negotiated flat rate
Customizations and enhancements are billed at an hourly rate.