I just purchased one Doceri Desktop license ($30) and the Camtasia for Mac Educational License ($75). Up until now I've only done desktop screencasting with Screencast-o-matic (free and web-based with a 15 minute video limit) and with Screenium for Mac ($40).
I am looking forward to learning all there is to know about Doceri and Camtasia. YouTube has some great training videos on both, so I hope to become adept at both soon.
I've done a lot of screencasts with iPad apps, but having desktop versions make it easier to screencast "how to use the Web" videos.
