Yes, both LiveAgent and HelpDesk offer a Free Trial.
LiveAgent is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
HelpDesk is designed for Large Enterprises, Medium Business and Small Business.
Pricing for LiveAgent Starts at $15/User/Month whereas for HelpDesk Starts at $29/User/Month when Billed Yearly.
Some top alternatives to LiveAgent includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Freshservice, Freshdesk, ClickDesk, HelpDesk, SysAid, Jitbit Helpdesk, Desky, Help Scout, LabiDesk, LiveChat, Zendesk Chat, LiveHelpNow and Little SaaS Communication.
Some top alternatives to HelpDesk includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Freshservice, Freshdesk, SupportBee, Teamwork Desk, SysAid, Jitbit Helpdesk, Snappy, Helpspot, ReadyDesk, HelpdeskEddy, Help Desk Premier, Support.cc by 500apps and BoldDesk.