Convert Developed App from Titanium to Phonegap

I have a fully developed mobile app that needs to be adapted for use by my company. The app features a navigation bar and 5 sections including Home, Fact Sheets, Checklists, Map, and Contacts. All sections and functions in the app will be kept; only graphics and text will need to be updated to reflect my company's information. The app was written within Titanium Studio but needs to be converted, or recreated, using Phonegap. Once the app is in Phonegap, my company will take over future maintenance. I need a rough estimate on how much money it will take to get this app updated with our information and working in the Phonegap environment to determine if the funds are available to proceed.