Yes, both Salesforce Service Cloud and Volusion offer a Free Trial.
Salesforce Service Cloud is designed for Large Enterprises, Medium Business and Small Business.
Volusion is designed for Freelancers, Medium Business and Small Business.
Pricing for Salesforce Service Cloud Starts at $25/user/month when yearly whereas for Volusion Starts at $26.10/Month when Billed Yearly.
Some top alternatives to Salesforce Service Cloud includes Zendesk Support, Zoho Desk, Tidio Helpdesk, Freshservice, Freshdesk, LiveAgent, HelpDesk, SysAid, Jitbit Helpdesk, HubSpot Service Hub, Help Scout, UseDesk, LabiDesk, AzureDesk, HESK and BoldDesk.
Some top alternatives to Volusion includes Spocket, Easyship, Spark Shipping, Dropshipper, Dropified, Zendrop, Shopify Plus, 2Ship, Shopify, Dropship SPY, Fulfill and Sell.xyz.