Force.com visualforce mobile app

Enter phone number and metadata as one string on mobile device. Split the incoming number into number and metadata. (optionally - lookup phone number after 10 digits entered without waiting for metadata) Verify if the number exists in SF org. If no, create new contact and create "New customer" activity, lookup today's interest in the database and add it to the contact. Display "Welcome, new customer" on the mobile device. Parse metadata and populate appropriate contact fields. If yes, update contact and create "Check-in" activity. Verify if the interest assigned to the contact matches today's interest. If not, add additional interest to contact. Display "Thank you for coming back" on mobile device. If additional interest was identified, "Thank for coming back. We will now keep you additionally informed about $INTEREST". This is obviously an incomplete spec for confidentiality reasons, but I think you get the idea. I will provide a complete spec. :) We will own the copyright for this code. The project will begin when we sign the first customer for the prototype. I am currently in budgeting stage. Please submit an estimate of what this piece would cost.