Camtasia is currently running a promotion where you can get version 3.0 for free, their latest version is 5.0 but with the promotion if/when you upgrade you will get 1/2 off ver 5.0.
All you need to do is
Download the free trial version
http://download.techsmith.com/camtas.../camtasiaf.exe
Then go to the promo page and fill out your info
Register for your Camtasia Studio 2 Software Key
Install the trial version and input the key that they email you.
Then you have a fully operational version of Camtasia 3.0 for free.
Hurry I'm not sure how much longer the promo will be running for.
Good luck