Titanium is free for building/distributed apps and hosting data using their mobile backend (ACS). The paid components are related to Appcelerator Platform, which is a suite of testing, performance, analytics, data and integration modules. If you're a hobbyist, you likely don't need the enterprise suite.
If you go with Phonegap / Cordova, I recommend looking into Appgyver's implementation which offers great tooling (cli), tight codebase (Angular) and an extended feature set for native components. They also have a great support for data integration and provide a nice visual editor (Composer).
Fwiw, I have been using Titanium since 2009 and have worked with many clients over the years as a consultant and trainer. I primarily use Titanium (Alloy) for rapid development and write native modules to extend the framework as needed. Expect about 85% cross-platform code coverage (business logic) and about 95% coverage for views/styles.
