The amount of money you could make back by running premium scripts is exponentially greater than the cost of the scripts in the first place. The most expensive script in the store is less than $20. When you get to the real world, you will see that software is extremely expensive, and osbot scripts are cheep for how sophisticated they are.
You wanna see expensive software?
http://www.autodesk.com/products/autodesk-inventor-family/buy
http://www.adobe.com/products/catalog/cs6._sl_id-contentfilter_sl_catalog_sl_software_sl_creativesuite6.html
http://www.visualstudio.com/en-us/products/visual-studio-professional-with-msdn-vs#Fragment_PricingHeader
http://www.esri.com/software/arcgis/arcgis-for-desktop/pricing