Yes, both Zendesk Talk and Nextiva offer a Free Trial.
Zendesk Talk is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Nextiva is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Zendesk Talk Starts at $9/User/Month whereas for Nextiva Starts at $18.95/User/Month when Billed Yearly.
Some top alternatives to Zendesk Talk includes Nextiva, TalkDesk, uContact, HoduCC, Call Center Studio, TelebuHub, VoxDesk and Freshdesk Contact Center (Formerly Freshcaller).
Some top alternatives to Nextiva includes uContact, Call Center Studio and OmniOMS Customer Communication Management Suite.