You are welcome to download the Free Edition of any of our products to experiment with the functionality, capabilities, etc., and to create a demonstration system. You can also post questions on these support forums for assistance (we respond on a best effort basis, at least once per week). All for free.
If you would like a trial license (which enables all features) and support during your installation process you would need to purchase a trial edition (priced at 50% of the Commercial Unlimited edition). In return we will help you get a complete functional demo up and running. As well, since there is no difference in the code base between the Free and Commercial Editions, your client can simply add a license file and turn the demonstration system into a production system. Will will also credit this amount towards the final sale if you decide to purchase the Commercial Unlimited edition.
Note: Trial licenses impose limitations to prevent the software from running indefinitely.