Yes, both osTicket and HelpDesk offer a Free Trial.
osTicket is designed for Individuals, Large Enterprises, Medium Business and Small Business.
HelpDesk is designed for Large Enterprises, Medium Business and Small Business.
Pricing for osTicket Starts at $9/User/Month whereas for HelpDesk Starts at $29/User/Month when Billed Yearly.
Some top alternatives to osTicket includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Freshservice, Jira Service Desk, Freshdesk, HelpDesk, SysAid, UVdesk, Jitbit Helpdesk, eStreamDesk, ReadyDesk, Spiceworks Help Desk, HESK, BoldDesk and GLPI.
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.