Yes, both OpenCart and HelpOnClick offer a Free Trial.
OpenCart is designed for Freelancers, Medium Business and Small Business.
HelpOnClick is designed for Large Enterprises, Medium Business and Small Business.
The starting price of HelpOnClick begins at $7.20/User/Month when Billed Yearly, while pricing details for OpenCart are unavailable.
Some top alternatives to OpenCart includes and undefined.
Some top alternatives to HelpOnClick includes ZoomInfo Chat, ClickDesk, LiveAgent, LiveChat, Crisp, DeskMoz, MyLiveChat, Zendesk Chat, Provide Support, WebsiteAlive and Smartchat.