How to buy a SaschArt plugin:
1. Download the demo from http://vst.saschart.com.
2. Click on Get Unlock Key from plugin interface.
3. Login/register to your account at http://vst.saschart.com/members/index.php, then pay the product.
4. After payment you will be redirect to your account where will find the unlock key to convert demo version to commercial. Not additional download required.