Unfortunately it isn't possible to provide a demo version as it will just contain all functionality and will work forever. Please check the demo pages of the plugin, the product pages and in the Documentation how the plugin works and feels. If you have specific questions about the functionalities, just let us know!
We can't give you a discount as we are exclusively selling our plugins via the Envato Marketplaces. If you would like to receive a discount for what reason, you should try to contact them.